| Date | Value |
|---|---|
| Sep 18, 2015 18:12 | 0.04 ppm |
| Aug 28, 2014 14:12 | 12 ppm |
| Apr 21, 2014 09:35 | 0.00 ppm |
| Mar 28, 2014 07:25 | 0.00 ppm |
| Mar 13, 2014 17:36 | 0.00 ppm |
| Mar 7, 2014 12:11 | 0.00 ppm |
| Jan 27, 2014 17:59 | 0.20 ppm |
| Dec 19, 2013 12:36 | 0.00 ppm |
| Dec 11, 2013 03:04 | 0.00 ppm |