| Date | Value |
|---|---|
| Jun 10, 2019 23:23 | 10 ppm |
| Jun 2, 2019 12:43 | 6 ppm |
| Jun 1, 2019 16:59 | 0.02 ppm |
| May 23, 2019 14:33 | 1 ppm |
| May 19, 2019 12:57 | 1 ppm |
| May 16, 2019 14:39 | 1 ppm |
| May 16, 2019 14:39 | 0.00 ppm |
| Sep 1, 2016 19:51 | 0.00 ppm |
| Aug 18, 2016 07:07 | 1.5 ppm |
| Aug 14, 2016 16:06 | 1.5 ppm |
| Jul 31, 2016 20:19 | 3 ppm |
| Jul 27, 2016 16:49 | 2.5 ppm |
| Jul 17, 2016 10:12 | 0.00 ppm |