| Date | Value |
|---|---|
| Mar 25, 2014 15:11 | 0.25 ppm |
| Mar 14, 2014 22:12 | 0.25 ppm |
| Mar 7, 2014 20:29 | 0.05 ppm |
| Mar 1, 2014 17:38 | 0.25 ppm |
| Jan 26, 2014 17:17 | 0.00 ppm |
| Dec 3, 2013 19:39 | 0.00 ppm |
| Nov 25, 2013 21:51 | 0.10 ppm |
| Oct 31, 2013 15:56 | 0.10 ppm |
| Oct 26, 2013 22:09 | 0.00 ppm |
| Sep 15, 2013 17:44 | 0.25 ppm |
| Sep 2, 2013 20:27 | 0.25 ppm |