| Date | Value |
|---|---|
| Oct 30, 2014 20:53 | 1540 ppm |
| Oct 20, 2014 20:25 | 1500 ppm |
| Oct 12, 2014 14:19 | 1280 ppm |
| Sep 23, 2014 19:17 | 1300 ppm |
| Sep 21, 2014 14:06 | 1260 ppm |
| Sep 16, 2014 10:39 | 1320 ppm |
| Aug 30, 2014 12:50 | 1300 ppm |
| Aug 15, 2014 10:33 | 1440 ppm |
| Aug 3, 2014 14:44 | 1640 ppm |
| Jul 25, 2014 01:23 | 1640 ppm |