| Date | Value |
|---|---|
| Sep 14, 2016 19:25 | 0.03 ppm |
| Jun 15, 2016 00:51 | 0.00 ppm |
| Jun 3, 2016 14:12 | 0.00 ppm |
| May 25, 2016 23:43 | 0.00 ppm |
| Mar 7, 2016 18:56 | 0.00 ppm |
| Jan 12, 2016 17:05 | 0.03 ppm |
| Oct 3, 2015 11:34 | 0.10 ppm |
| Sep 7, 2015 22:18 | 0.02 ppm |
| Aug 3, 2015 16:22 | 0.20 ppm |