| Date | Value |
|---|---|
| Nov 5, 2014 18:51 | 0.08 ppm |
| Apr 25, 2014 15:56 | 2 ppm |
| Apr 5, 2014 14:47 | 0.14 ppm |
| Feb 13, 2014 11:05 | 2.5 ppm |
| Jan 8, 2014 15:53 | 2.5 ppm |
| Oct 18, 2013 19:52 | 0.71 ppm |
| Sep 18, 2013 17:26 | 0.66 ppm |
| Jun 25, 2013 22:06 | 0.25 ppm |
| Apr 25, 2013 19:23 | 0.25 ppm |
| Feb 15, 2013 17:40 | 2 ppm |
| Jan 24, 2013 10:19 | 1.2 ppm |