| Date | Value |
|---|---|
| Jan 10, 2019 16:09 | 23 ppm |
| Oct 6, 2018 16:06 | 0.00 ppm |
| Aug 1, 2018 20:31 | 0.10 ppm |
| Jul 31, 2018 21:50 | 0.10 ppm |
| Jul 6, 2018 22:58 | 0.00 ppm |
| May 29, 2018 21:55 | 0.00 ppm |
| May 6, 2018 22:20 | 0.00 ppm |
| Apr 19, 2018 22:23 | 0.00 ppm |
| Apr 18, 2018 22:23 | 0.00 ppm |
| Apr 15, 2018 22:21 | 0.10 ppm |