| Date | Value |
|---|---|
| Apr 2, 2013 21:12 | 1 ppm |
| Mar 18, 2013 21:06 | 2 ppm |
| Mar 3, 2013 05:37 | 4 ppm |
| Feb 5, 2013 21:26 | 50 ppm |
| Jan 1, 2013 20:33 | 5 ppm |
| Dec 21, 2012 15:41 | 10 ppm |
| Dec 11, 2012 20:12 | 2 ppm |
| Dec 1, 2012 12:32 | 10 ppm |
| Nov 12, 2012 22:08 | 2 ppm |
| Nov 5, 2012 18:50 | 20 ppm |
| Oct 1, 2012 21:55 | 25 ppm |
| Sep 3, 2012 19:59 | 25 ppm |
| Aug 31, 2012 14:11 | 25 ppm |
| Aug 6, 2012 22:18 | 25 ppm |
| Jul 30, 2012 21:36 | 25 ppm |
| Jul 20, 2012 12:25 | 25 ppm |