| Date | Value |
|---|---|
| Dec 26, 2019 13:58 | 5 ppm |
| Nov 23, 2019 17:00 | 3 ppm |
| Nov 15, 2019 13:54 | 3 ppm |
| Oct 13, 2019 16:58 | 3 ppm |
| Oct 8, 2019 00:22 | 5 ppm |
| Sep 29, 2019 20:43 | 7.5 ppm |
| Sep 29, 2019 14:46 | 15 ppm |
| Sep 22, 2019 23:34 | 10 ppm |
| Aug 31, 2019 14:15 | 5 ppm |
| Aug 25, 2019 13:57 | 50 ppm |