| Date | Value |
|---|---|
| May 8, 2016 19:59 | 30 ppm |
| Apr 14, 2016 06:43 | 15 ppm |
| Apr 2, 2016 13:02 | 22 ppm |
| Mar 15, 2016 09:56 | 13 ppm |
| Mar 11, 2016 09:29 | 15 ppm |
| Mar 9, 2016 18:23 | 16 ppm |
| Mar 8, 2016 19:52 | 20 ppm |
| Feb 28, 2016 13:44 | 8 ppm |
| Jan 18, 2016 18:18 | 9 ppm |
| Jan 13, 2016 18:56 | 8 ppm |
| Dec 24, 2015 11:05 | 8 ppm |
| Dec 20, 2015 20:11 | 9 ppm |
| Dec 17, 2015 20:27 | 8 ppm |