| Date | Value |
|---|---|
| Sep 18, 2013 12:36 | 7.5 ppm |
| Jul 6, 2013 11:23 | 7.6 ppm |
| Apr 9, 2013 17:08 | 7.4 ppm |
| Apr 7, 2013 15:39 | 6.5 ppm |
| Mar 30, 2013 22:13 | 6.9 ppm |
| Mar 30, 2013 22:12 | 6.4 ppm |
| Feb 3, 2013 20:38 | 8 ppm |
| Nov 26, 2012 16:07 | 8 ppm |
| Nov 25, 2012 16:07 | 8 ppm |
| Nov 25, 2012 07:07 | 8 ppm |