| Date | Value |
|---|---|
| May 16, 2019 19:36 | 1170 ppm |
| May 13, 2019 05:00 | 1224 ppm |
| Apr 15, 2019 06:39 | 1291 ppm |
| Mar 18, 2019 07:39 | 1271 ppm |
| Feb 18, 2019 07:39 | 1288 ppm |
| Jan 27, 2019 05:00 | 1080 ppm |
| Jun 4, 2018 07:39 | 1195 ppm |
| May 10, 2018 09:09 | 1230 ppm |
| Apr 29, 2018 09:32 | 1380 ppm |
| Apr 20, 2018 07:51 | 1302 ppm |
| Apr 12, 2018 14:41 | 1320 ppm |
| Mar 21, 2018 11:18 | 1351 ppm |