G0.091-0.662 Bre12 Comparable features with peak at 23 km/s G0.212-0.000 Bre12 The feature at 49.5 km/s was stronger in our observation G0.315-0.200 Gay94, Bre12 Similar to Gay94, but the peak was at ~20 km/s and the feature at 14 km/s vanished in Bre12 and our detections G0.496+0.188 Bre12 The feature at 1 km/s varied from 18 Jy to 43 Jy, multiple weak features were detected in the range of -10 to -3 km/s in our observation G0.546-0.851 Cas93, Cas95, Bre12 Multiple features were detected in our observation and features less than 15 km/s were similar to Bre12a, while those exceed 15 km/s were stronger G0.644-0.042 Cas93, Cas95, Bre12 Similar spectra G0.651-0.048 Bre12 The feature at 68.7 km/s disappeared in our observation G1.718-0.087 Bre12 Single feature at 12 km/s with flux varied from 0.9 Jy to 2 Jy G2.535+0.198 Bre12 Similar spectra G2.703+0.040 Bre12 No changes G3.253+0.018 Bre12 Similar spectra G4.393+0.078 Bre12 Similar spectra G6.188-0.358 Bre12 New feature appeared at 28.5 km/s G6.587-0.191 Bre12 The peak flux varied from 3 Jy to 6 Jy G6.609-0.082 Bre12 The peak flux varied from 11 Jy to 22.5 Jy G6.795-0.257 Gay94, Bre12 New feature at 27 km/s G7.165+0.131 Bre12 No changes G7.631-0.109 Bre12 No changes G8.317-0.096 Bre12 No changes G8.669-0.355 Cas93, Cas95, Bre12 No changes G8.682-0.368 Cas93, Cas95, Bre12 The profile was similar but the flux varied from 8.1 Jy (Bre12) to 25.75 Jy G8.831-0.028 Bre12 Similar G9.618+0.193 Cas93, Cas95, Bre12 Periodic variation(see Section 3.2) G9.621+0.195 Cas93, Cas95, Bre12 No changes G9.985-0.027 Bre12 No changes G10.320-0.258 Bre14 Similar spectra G10.322-0.159 Bre14 No changes G10.342-0.142 Bre14 The feature at 7.5 km/s became the strongest one G10.444-0.018 Cas95, Bre14 The strongest feature changed from 72 (Cas95, Bre14) to 70.8 km/s G10.472+0.027 Cas93, Cas95, Bre14 The peak at 75 km/s was ~12 Jy in previous observation while it was 29.25 Jy in our observation G10.626-0.384 Cas95, Bre14 The feature at 5 km/s was the strongest in all observations G10.958+0.022 Bre14 Similar spectra G11.109-0.114 Bre14 No changes G11.497-1.485 Gay94, Bre14 No changes G11.903-0.141 Cas93, Cas95, Bre14 No changes G11.936-0.615 Cas93, Cas95, Bre14 Similar spectra G12.025-0.031 Cas93, Cas95, Bre14 No changes G12.112-0.126 Bre14 New feature appeared at 39.5 km/s G12.526+0.016 Bre14 Similar spectra G12.624-0.016 Bre14 The strongest feature changed from 21.6 to 24.8 km/s G12.680-0.182 Cas95, Bre14 Similar spectra G12.888+0.489 Cas95, Bre14 This source exhibited periodicity in both 12.2 and 6.7 GHz (see Section 3.2) G12.908-0.260 Cas93, Cas95, Bre10, Bre14 The feature at 39.4 km/s changed from 16 Jy (Bre10) to ~43 Jy, but the feature at 39.8 km/s was similar G14.101+0.086 Bla04, Bre14 No changes G14.389-0.020 Bre14 Similar spectra G14.603+0.016 Bre14 No changes G15.034-0.677 Cas93, Cas95, Bre14 The strongest feature changed from 23.4 (Bre14) to 21.5 km/s. G15.094+0.191 Bre14 No changes G16.301-0.196 Bre14 The strongest feature changed from 51.4 (Bre14) to 52.3 km/s G16.585-0.050 Cas95, Bre14 The strongest feature changed from 65.9 (Cas95, Bre14) to 64.7 km/s G18.072+0.077 Bre14 Similar spectra G18.262-0.243 Bre14 The peak at 79.1 km/s changed from 5.2 Jy (Bre14) to 1.33 Jy G18.341+1.768 Bre14 Similar spectra G18.873+0.053 Bre14 A burst increased (11.39 Jy) in our observation, compared with that reported by Bre16 with the peak of 0.6 Jy G19.008-0.029 Bre14 Similar spectra G19.364-0.030 Bre14 No changes G19.486+0.150 Cas95, Bla04, Bre14 Similar spectra G20.237+0.065 Cas95, Bre16 Similar spectra G20.239+0.064 Cas95, Bre16 The profile was stable, but the peak increased from 0.5 Jy (Bre14) to 5.6 Jy G21.406-0.254 Bre16 No changes G22.334-0.154 Bre16 No changes G22.435-0.169 Cas93, Cas95, Bre16 Similar spectra G23.009-0.410 Cas93, Cas95, Bre16 New feature at 82.5 km/s G23.206-0.377 Bla04, Bre16 Similar spectra G23.256-0.240 Bre16 Similar spectra G23.389+0.185 Bre10, Bre16 The peak decreased from 2.2 Jy (Bre10) to 0.84 Jy G23.436-0.184 Cas93, Cas95, Bre10, Bre16 The peak feature increased from 3.4 Jy (Bre10) to 13.1 Jy G23.656-0.127 Bre16 Similar spectra G23.706-0.198 Gay94, Bla04, Bre16 The feature at 76 km/s became the strongest in our observation G24.147-0.009 Bla04, Bre16 No changes G24.328+0.144 Cas95, Bre16 Similar spectra G24.493-0.038 Bre16 Similar spectra G25.709+0.043 Bla04, Bre16 The maser flux density in our observation was weaker than those reported by Bla04 and Bre16 with the peaks of 213.7 Jy and 144 Jy at 95.6 km/s, respectively G25.825-0.178 Bla04, Bre16 Similar spectra G27.219+0.260 Bla04, Bre16 Similar spectra G27.221+0.136 Bre10, Bre16 The peak feature increased from 3.2 Jy (Bre10) to 11.11 Jy G27.286+0.150 Bre16 Similar spectra G27.365-0.165 Cas95, Bre16 Our detection was similar to Bre16, but the peak feature changed from 99.5 to 100.3 km/s G28.010-0.426 Bre16 New feature appeared at 25 km/s G28.147-0.004 Cas95, Bre10, Bre16 Similar spectra G28.304-0.387 Gay94, Bre16 Similar spectra G28.817+0.364 Bre16 Similar spectra G28.832-0.252 Cas93, Cas95, Bre16 Similar spectra G29.319-0.161 Bre16 The feature at 43 km/s became the strongest in our observation G29.862-0.044 Cas93, Cas95, Bre10, Bre16 Similar spectra G29.955-0.016 Cas93, Cas95, Bre10, Bre16 Similar spectra G29.978-0.047 Cas93, Cas95, Bre10, Bre18 No changes G30.198-0.169 Cas93, Cas95, Bre10, Bre16 The feature at 108 km/s was no longer the strongest G30.224-0.180 Cas95 This maser has not been detected in Bre16 G30.317+0.070 Bre16 Two new spectral features were detected in the velocity range of 30--34 km/s in our observation G30.760-0.052 Cas95, Bre10, Bre16 No changes G30.779+0.230 Cas95, Bre16 Similar spectra G30.788+0.203 Bre16 Similar spectra G30.817-0.056 Cas95, Bre10, Bre16 Similar spectra G30.897+0.161 Bre16 Similar spectra G30.972-0.141 Bre16 Similar fluxs, but the feature at 78 km/s has not been detected in our survey G31.046+0.356 Bre16 Similar spectra G31.280+0.061 Cas93, Cas95, Bre10, Bre16 The feature at 110.5 km/s increased from 14.7 Jy (Bre16) to 74.01 Jy G31.411+0.307 Cas95, Bre10, Bre16 The peak flux changed from 1.5 Jy (Bre16) to 4.23 Jy G33.092-0.072 Cas95, Bre16 The peak flux increased from 2.3 Jy (Bre16) to 10.21 Jy G33.132-0.091 Cas95, Bre10, Bre16 Similar spectra G33.392+0.009 Bre16 Similar spectra G33.641-0.227 Bla04, Bre16 The strongest feature changed from 60.3 km/s (Bre16) to 58.7 km/s G34.244+0.133 Cas95, Bre10, Bre16 Similar spectra G34.257+0.153 Cas95, Bre16 G34.244+0.133 barely had influence to this source which was similar to Bre16 and Cas95 G34.791-1.386 Bre16 Similar spectra G35.024+0.349 Cas95, Bre10, Bre16 Similar spectra G35.197-0.743 Cas93, Cas95, Bre16 The strongest feature changed from 30.5 (Bre16) to 28.3 km/s G35.200-1.736 Cas93, Cas95, Bre16 The feature at 41 km/s kept fading, from ~100 Jy (Cas93, Cas95) to ~25 Jy (Bre16), and ~2 Jy in our detection G35.792-0.174 Bre16 No much changes G36.115+0.552 Bre16 The feature at 75 km/s was almost the same and new feature appeared at 72.5 and 76 km/s in our observation G37.043-0.035 Bre16 The peak at 83.8 km/s increased from 2.7 Jy (Bre16) to 9.55 Jy G37.429+1.517 Gay94, Bre16 The peak flux grown from 90 Jy (Bre16) to 149.18 Jy G37.479-0.104 Bre16 The strongest feature changed from 63 to 61.2 km/s G37.546-0.111 Bla04, Bre16 Similar spectra G38.119-0.228 Bre16 We detected a new weak feature (~0.5 Jy) at the velocity of 74 km/s G39.100+0.491 Bre16 Peak feature increasesed from 2.1 Jy (Bre16) to 6.98 Jy G40.281-0.219 Bre16 Similar spectra G40.425+0.700 Bre16 Two weak features (~1 Jy) in the velocity range of 10--11 km/s were newly detected in our observations. G41.347-0.136 Bre16 Similar spectra G42.034+0.190 Bre16 The peak feature changed from 2.6 Jy (Bre16) to 8.92 Jy G42.698-0.147 Bre16 The feature at -46.8 km/s kept stable while that at -47 km/s changed from ~1 Jy (Bre16) to 2 Jy G43.149+0.013 Cas95, Bla04, Bre16 New feature at ~21.5 km/s. G43.890-0.784 Bla04, Bre16 The strongest feature changed from 48 to 51.8 km/s and both features were comparable G45.467+0.053 Cas95, Bre16 No changes G45.804-0.355 Bre16 No changes G49.042-1.078 Bre16 The strongest feature was similar G49.265+0.311 Bre16 The features at range of -20 to -10 km/s were no longer detectable in our observation G49.349+0.412 Bre16 The feature at 68.3 km/s changed from 2.8 Jy (Bre16) to 7.2 Jy G49.415+0.325 Bla04, Bre16 The feature at -1.9 km/s with a peak flux density of 27.8 Jy reported by Bla04 was not detected, but a new feature at -14 km/s was detected in our detection G49.469-0.370 Cas95, Bre16 The peak feature increased from 0.5 Jy (Bre16) to 10.2 Jy and feature at the velocity bigger than 60 km/s were similar to previous work G49.482-0.401 Bre16 Similar spectra G49.599-0.249 Bre16 The strongest feature switched from 63.5 to 64 km/s, but the peak flux was similar G52.198+0.723 Bre16 Similar spectra G52.662-1.092 Bla04, Bre16 Similar spectra G59.782+0.064 Cas95 Bre16 did not detect this source, but compared to Cas95 it shown no changes G188.946+0.885 Cas93, Cas95, Bre12 This source was periodic and burst, but the profile of the spectra was similar (see Section 3.2) G189.029+0.783 Cas95 This source has not been reported in Bre12. The peak features at the range of 8 to 10 km/s were no longer detectable in our survey, only the feature at 10.5 km/s was detectable G192.600-0.048 Cas95, Bre10, Bre12 A burst detected from this source, from 0.5 Jy (Bre12) to 200 Jy in our observation. This source was over 65 Jy in Cas95 (see Section 3.2) G196.453-1.677 Cas95 Similar spectra G213.704-12.596 Cas95, Bre10, Bre12 The peak feature changed from 14 Jy (Bre10) to 36.15 Jy in our observation G232.620+0.995 Cas95, Bre12 The peak feature increased from 27 Jy (Bre12) to 86.8 Jy in our observation G357.923-0.336 Bre12 Similar spectra G358.370-0.467 Bre12 Similar spectra G358.808-0.085 Bre12 Similar spectra G358.841-0.737 Bre12 Similar spectra G359.614-0.243 Bre12 The strongest feature increased from 5.7 Jy (Bre12) to 13.35 Jy in our detection