| Date | Value |
|---|---|
| Jun 24, 2018 12:24 | 1480 ppm |
| Jun 18, 2018 18:00 | 1500 ppm |
| Jun 5, 2018 20:20 | 1300 ppm |
| Jun 3, 2018 14:24 | 1300 ppm |
| Jun 3, 2018 13:58 | 1220 ppm |
| Jun 2, 2018 15:32 | 1260 ppm |
| May 30, 2018 12:54 | 1340 ppm |
| May 28, 2018 10:25 | 1100 ppm |
| May 20, 2018 15:34 | 1460 ppm |
| May 17, 2018 21:26 | 1460 ppm |
| May 14, 2018 06:30 | 1150 ppm |
| May 12, 2018 17:29 | 1200 ppm |