| Date | Value |
|---|---|
| May 31, 2015 09:32 | 0.00 ppm |
| Sep 24, 2014 18:49 | 0.00 ppm |
| Aug 17, 2014 16:54 | 0.25 ppm |
| Jun 21, 2014 08:10 | 0.00 ppm |
| Feb 8, 2014 16:29 | 0.00 ppm |
| Nov 17, 2013 11:38 | 0.00 ppm |
| Jun 30, 2013 18:49 | 2.5 ppm |
| Apr 1, 2013 14:08 | 10 ppm |
| Mar 24, 2013 11:48 | 5 ppm |
| Mar 18, 2013 20:54 | 10 ppm |