| Date | Value |
|---|---|
| Feb 27, 2021 10:17 | 1500 ppm |
| Dec 6, 2020 10:08 | 1440 ppm |
| Oct 22, 2020 10:25 | 1280 ppm |
| Aug 30, 2020 08:41 | 1520 ppm |
| Aug 9, 2020 09:21 | 1440 ppm |
| Aug 2, 2020 08:31 | 1440 ppm |
| Jul 26, 2020 08:42 | 1280 ppm |
| Jul 18, 2020 07:50 | 1420 ppm |
| Jul 12, 2020 13:34 | 1420 ppm |
| Jul 4, 2020 15:00 | 1500 ppm |
| Jun 27, 2020 09:14 | 1520 ppm |
| Jun 20, 2020 09:16 | 1520 ppm |
| Jun 14, 2020 08:29 | 1360 ppm |