| Date | Value |
|---|---|
| Jan 26, 2015 15:41 | 1300 ppm |
| Jan 9, 2015 19:57 | 1450 ppm |
| Dec 22, 2014 11:19 | 1250 ppm |
| Dec 14, 2014 15:06 | 1200 ppm |
| Dec 8, 2014 15:32 | 1250 ppm |
| Dec 5, 2014 20:25 | 1350 ppm |
| Sep 24, 2014 14:50 | 1200 ppm |
| Aug 20, 2014 13:23 | 1260 ppm |
| Aug 18, 2014 14:45 | 1250 ppm |
| Aug 17, 2014 16:25 | 1200 ppm |
| Aug 15, 2014 16:14 | 1200 ppm |
| Aug 14, 2014 15:22 | 1200 ppm |