| Date | Value |
|---|---|
| Dec 13, 2016 23:08 | 0.06 ppm |
| Jul 5, 2016 01:00 | 0.06 ppm |
| Apr 25, 2016 01:14 | 0.06 ppm |
| Oct 2, 2015 23:49 | 0.03 ppm |
| Jul 24, 2015 21:42 | 0.06 ppm |
| Jul 12, 2015 01:26 | 0.03 ppm |
| Jun 16, 2015 00:52 | 0.03 ppm |
| May 31, 2015 05:35 | 0.06 ppm |
| May 18, 2015 21:59 | 0.09 ppm |
| Feb 23, 2015 23:15 | 0.06 ppm |