| Date | Value |
|---|---|
| May 22, 2021 00:37 | 450 ppm |
| May 18, 2021 21:34 | 445 ppm |
| May 18, 2021 01:51 | 460 ppm |
| May 12, 2021 23:41 | 401 ppm |
| May 11, 2021 23:06 | 422 ppm |
| May 10, 2021 22:30 | 417 ppm |
| May 7, 2021 23:44 | 401 ppm |
| May 5, 2021 22:31 | 398 ppm |
| May 4, 2021 23:38 | 371 ppm |