| Date | Value |
|---|---|
| Aug 20, 2020 20:32 | 430 ppm |
| Jun 21, 2020 21:01 | 440 ppm |
| May 10, 2020 20:07 | 480 ppm |
| Apr 25, 2020 18:44 | 460 ppm |
| Apr 19, 2020 17:29 | 460 ppm |
| Apr 5, 2020 18:31 | 445 ppm |
| Dec 15, 2019 11:29 | 475 ppm |
| Dec 6, 2019 21:35 | 460 ppm |
| Dec 5, 2019 20:03 | 460 ppm |
| Dec 4, 2019 21:10 | 440 ppm |
| Dec 2, 2019 18:34 | 430 ppm |
| Nov 19, 2019 17:50 | 450 ppm |
| Nov 10, 2019 08:09 | 460 ppm |
| Nov 7, 2019 08:01 | 490 ppm |
| Nov 5, 2019 08:01 | 480 ppm |