| Date | Value |
|---|---|
| Jun 7, 2014 20:14 | 1.5 ppm |
| Oct 10, 2013 16:51 | 1 ppm |
| Jun 29, 2013 16:55 | 2.5 ppm |
| May 7, 2013 20:36 | 1.8 ppm |
| Apr 13, 2013 20:05 | 1.1 ppm |
| Mar 31, 2013 11:17 | 0.01 ppm |
| Mar 12, 2013 17:48 | 0.60 ppm |
| Mar 2, 2013 13:06 | 1.5 ppm |
| Feb 24, 2013 09:55 | 1 ppm |
| Dec 23, 2012 15:02 | 1.5 ppm |