| Date | Value |
|---|---|
| Mar 21, 2020 20:16 | 20 ppm |
| Mar 14, 2020 00:21 | 30 ppm |
| Mar 4, 2020 00:30 | 100 ppm |
| Feb 29, 2020 23:31 | 80 ppm |
| Feb 28, 2020 00:45 | 80 ppm |
| Feb 25, 2020 23:58 | 60 ppm |
| Feb 24, 2020 01:40 | 20 ppm |
| Feb 21, 2020 00:36 | 7.5 ppm |
| Feb 18, 2020 23:55 | 7.5 ppm |
| Feb 17, 2020 19:11 | 15 ppm |
| Feb 15, 2020 03:53 | 20 ppm |
| Feb 12, 2020 23:40 | 20 ppm |
| Feb 10, 2020 22:50 | 20 ppm |
| Feb 9, 2020 01:16 | 5 ppm |