| Date | Value |
|---|---|
| Feb 26, 2014 19:15 | 0.17 ppm |
| Dec 21, 2013 17:26 | 0.00 ppm |
| Dec 16, 2013 19:48 | 0.07 ppm |
| Nov 25, 2013 19:52 | 0.05 ppm |
| Jul 26, 2013 08:37 | 0.00 ppm |
| Jul 8, 2013 20:01 | 0.14 ppm |
| Jun 20, 2013 20:26 | 0.05 ppm |
| Jun 7, 2013 15:59 | 0.06 ppm |
| May 20, 2013 20:31 | 0.08 ppm |
| May 20, 2013 16:10 | 0.00 ppm |
| May 18, 2013 11:40 | 0.10 ppm |
| May 15, 2013 21:45 | 0.08 ppm |
| Apr 8, 2013 20:35 | 0.08 ppm |