| Date | Value |
|---|---|
| Nov 24, 2019 01:38 | 365 ppm |
| Oct 19, 2019 21:52 | 400 ppm |
| Oct 6, 2019 21:16 | 390 ppm |
| Sep 15, 2019 01:00 | 400 ppm |
| Aug 29, 2019 01:57 | 435 ppm |
| Aug 16, 2019 22:49 | 415 ppm |
| Jul 27, 2019 01:24 | 425 ppm |
| Jul 24, 2019 02:14 | 420 ppm |
| Jul 20, 2019 01:53 | 440 ppm |
| Jul 17, 2019 23:06 | 420 ppm |
| Jul 17, 2019 02:47 | 440 ppm |
| Jul 14, 2019 19:10 | 425 ppm |
| Jul 12, 2019 01:59 | 440 ppm |
| Mar 24, 2019 16:36 | 450 ppm |
| Mar 19, 2019 21:24 | 460 ppm |