| Date | Value |
|---|---|
| Oct 14, 2016 10:52 | 340 ppm |
| Oct 9, 2016 18:24 | 350 ppm |
| Jul 7, 2016 17:53 | 440 ppm |
| Jun 12, 2016 13:39 | 420 ppm |
| Jun 8, 2016 17:34 | 390 ppm |
| Jun 3, 2016 20:09 | 420 ppm |
| May 30, 2016 20:11 | 430 ppm |
| May 29, 2016 11:21 | 430 ppm |
| May 28, 2016 16:52 | 410 ppm |
| May 16, 2016 17:54 | 410 ppm |
| May 6, 2016 20:18 | 430 ppm |
| May 5, 2016 11:53 | 500 ppm |