| Date | Value |
|---|---|
| Aug 8, 2018 00:17 | 1400 ppm |
| Jul 20, 2018 00:56 | 1400 ppm |
| Jul 11, 2018 22:43 | 1320 ppm |
| Jul 5, 2018 23:48 | 1200 ppm |
| Jul 2, 2018 23:30 | 1120 ppm |
| Jun 20, 2018 23:45 | 1240 ppm |
| Jun 13, 2018 23:53 | 1400 ppm |
| Jun 5, 2018 22:36 | 1400 ppm |
| Jun 5, 2018 01:00 | 1120 ppm |
| Jun 2, 2018 00:38 | 1400 ppm |
| May 29, 2018 00:48 | 1520 ppm |
| May 28, 2018 02:02 | 1600 ppm |
| May 22, 2018 01:38 | 1600 ppm |