| Date | Value |
|---|---|
| Jul 27, 2014 23:59 | 1320 ppm |
| Jun 29, 2014 07:46 | 1260 ppm |
| Jun 14, 2014 21:26 | 1320 ppm |
| Jun 6, 2014 00:05 | 1290 ppm |
| Jun 3, 2014 07:04 | 1260 ppm |
| May 27, 2014 21:20 | 1280 ppm |
| May 22, 2014 03:23 | 1300 ppm |
| May 17, 2014 20:56 | 1260 ppm |
| May 15, 2014 03:38 | 1330 ppm |