| Date | Value |
|---|---|
| Oct 7, 2017 08:20 | 1380 ppm |
| Sep 30, 2017 08:20 | 1470 ppm |
| Sep 27, 2017 21:29 | 1470 ppm |
| Sep 23, 2017 13:12 | 1470 ppm |
| Sep 16, 2017 13:21 | 1500 ppm |
| Aug 1, 2017 07:59 | 1480 ppm |
| Jul 15, 2017 18:38 | 1520 ppm |
| Jul 4, 2017 22:04 | 1270 ppm |
| Jul 2, 2017 19:22 | 1275 ppm |
| Jul 1, 2017 19:32 | 1290 ppm |
| Jun 25, 2017 19:43 | 1450 ppm |
| Jun 24, 2017 16:33 | 1470 ppm |