| Date | Value |
|---|---|
| Dec 7, 2020 15:48 | 0.02 ppm |
| Dec 4, 2020 13:39 | 0.01 ppm |
| Dec 3, 2020 14:42 | 0.01 ppm |
| Dec 2, 2020 14:13 | 0.02 ppm |
| Dec 1, 2020 15:09 | 0.01 ppm |
| Nov 30, 2020 15:37 | 0.01 ppm |
| Nov 23, 2020 16:15 | 0.02 ppm |
| Oct 12, 2020 17:15 | 0.02 ppm |
| Sep 22, 2020 18:48 | 0.07 ppm |
| Sep 7, 2020 16:07 | 0.08 ppm |
| Aug 22, 2020 17:03 | 0.06 ppm |
| Aug 7, 2020 21:00 | 0.05 ppm |
| Jun 29, 2020 15:48 | 0.03 ppm |
| Jun 4, 2020 16:47 | 0.04 ppm |