| Date | Value |
|---|---|
| Dec 24, 2018 09:20 | 460 ppm |
| Jul 10, 2017 13:53 | 540 ppm |
| Jul 9, 2017 09:39 | 550 ppm |
| Jul 8, 2017 08:09 | 340 ppm |
| Aug 18, 2016 11:42 | 450 ppm |
| Aug 8, 2016 09:33 | 400 ppm |
| Jul 4, 2016 13:38 | 400 ppm |
| Jul 3, 2016 06:52 | 390 ppm |
| Jun 27, 2016 13:50 | 400 ppm |
| Jun 25, 2016 11:21 | 405 ppm |
| Jun 23, 2016 15:54 | 390 ppm |