| Date | Value |
|---|---|
| Sep 1, 2014 10:48 | 1440 ppm |
| Aug 27, 2014 21:50 | 1560 ppm |
| Aug 22, 2014 13:37 | 1420 ppm |
| Aug 14, 2014 00:00 | 1400 ppm |
| Jul 29, 2014 00:00 | 1360 ppm |
| Jul 20, 2014 00:00 | 1400 ppm |
| Dec 1, 2013 00:00 | 1560 ppm |
| Nov 24, 2013 00:00 | 1520 ppm |
| Oct 18, 2013 00:00 | 1250 ppm |