| Date | Value |
|---|---|
| Nov 4, 2020 02:14 | 380 ppm |
| Oct 19, 2020 20:45 | 400 ppm |
| Oct 12, 2020 19:21 | 360 ppm |
| Sep 28, 2020 21:28 | 400 ppm |
| Sep 13, 2020 23:11 | 400 ppm |
| Sep 9, 2020 00:28 | 400 ppm |
| Aug 18, 2020 18:16 | 460 ppm |
| Aug 12, 2020 00:29 | 440 ppm |
| Jul 30, 2020 15:44 | 460 ppm |
| Jul 20, 2020 20:21 | 500 ppm |