| Date | Value |
|---|---|
| Jul 27, 2014 23:48 | 415 ppm |
| Jul 1, 2014 06:50 | 410 ppm |
| Jun 29, 2014 07:38 | 425 ppm |
| Jun 27, 2014 05:25 | 430 ppm |
| Jun 14, 2014 21:20 | 430 ppm |
| Jun 6, 2014 00:12 | 425 ppm |
| Jun 3, 2014 06:57 | 390 ppm |
| May 27, 2014 21:29 | 410 ppm |
| May 22, 2014 03:13 | 400 ppm |
| May 17, 2014 20:47 | 410 ppm |
| May 15, 2014 03:31 | 410 ppm |
| May 14, 2014 02:43 | 410 ppm |