| Date | Value |
|---|---|
| Nov 25, 2014 19:29 | 1350 ppm |
| Nov 4, 2014 18:48 | 1500 ppm |
| Nov 29, 2013 18:12 | 1250 ppm |
| Nov 7, 2013 15:46 | 1250 ppm |
| Oct 30, 2013 14:09 | 1100 ppm |
| Oct 24, 2013 17:16 | 1250 ppm |
| Mar 11, 2013 16:13 | 800 ppm |
| Feb 28, 2013 17:48 | 1200 ppm |
| Feb 21, 2013 18:38 | 1100 ppm |
| Feb 19, 2013 10:55 | 1050 ppm |
| Feb 18, 2013 10:55 | 950 ppm |