| Date | Value |
|---|---|
| Dec 3, 2012 06:53 | 1320 ppm |
| Nov 28, 2012 06:19 | 1360 ppm |
| Nov 17, 2012 18:17 | 1320 ppm |
| Nov 9, 2012 03:11 | 1360 ppm |
| Nov 2, 2012 07:57 | 1320 ppm |
| Oct 24, 2012 07:54 | 1400 ppm |
| Oct 18, 2012 07:51 | 1320 ppm |
| Oct 11, 2012 07:48 | 1320 ppm |
| Oct 5, 2012 07:42 | 1440 ppm |
| Sep 29, 2012 07:37 | 1400 ppm |