| Date | Value |
|---|---|
| Dec 19, 2013 22:09 | 435 ppm |
| Dec 15, 2013 22:01 | 455 ppm |
| Dec 2, 2013 17:38 | 415 ppm |
| Nov 19, 2013 21:40 | 420 ppm |
| Nov 15, 2013 17:38 | 410 ppm |
| Nov 4, 2013 16:47 | 420 ppm |
| Nov 1, 2013 14:24 | 410 ppm |
| Oct 28, 2013 17:46 | 430 ppm |
| Oct 26, 2013 04:46 | 400 ppm |