| Date | Value |
|---|---|
| Jan 2, 2015 10:28 | 420 ppm |
| Nov 18, 2014 11:10 | 450 ppm |
| Nov 10, 2014 11:49 | 450 ppm |
| Nov 2, 2014 09:51 | 455 ppm |
| Oct 14, 2014 11:41 | 450 ppm |
| Oct 5, 2014 18:47 | 495 ppm |
| Aug 19, 2014 12:26 | 495 ppm |
| Aug 16, 2014 08:49 | 440 ppm |
| Aug 11, 2014 14:26 | 425 ppm |