| Date | Value |
|---|---|
| Sep 13, 2016 11:52 | 1300 ppm |
| Oct 20, 2014 21:57 | 1200 ppm |
| Aug 28, 2014 22:17 | 1280 ppm |
| Jul 22, 2014 22:28 | 1250 ppm |
| May 16, 2014 22:16 | 1250 ppm |
| Apr 22, 2014 21:23 | 1200 ppm |
| Mar 31, 2014 20:21 | 1250 ppm |
| Jan 12, 2014 11:10 | 1300 ppm |
| Nov 18, 2013 21:10 | 1280 ppm |
| Nov 3, 2013 11:53 | 1280 ppm |
| Oct 31, 2013 08:18 | 1230 ppm |
| Oct 29, 2013 20:19 | 1200 ppm |
| Oct 12, 2013 18:00 | 1300 ppm |