| Date | Value |
|---|---|
| Jan 11, 2019 11:00 | 435 ppm |
| Jan 9, 2019 23:20 | 430 ppm |
| Dec 15, 2017 12:15 | 320 ppm |
| Apr 10, 2017 22:30 | 455 ppm |
| Apr 8, 2017 16:10 | 455 ppm |
| Apr 7, 2017 16:43 | 465 ppm |
| Apr 5, 2017 23:19 | 460 ppm |
| Apr 3, 2017 15:29 | 460 ppm |
| Apr 2, 2017 15:29 | 460 ppm |
| Apr 1, 2017 15:29 | 460 ppm |
| Mar 20, 2017 15:02 | 485 ppm |
| Mar 17, 2017 17:10 | 490 ppm |