| Date | Value |
|---|---|
| Sep 14, 2015 11:24 | 390 ppm |
| Aug 31, 2015 09:53 | 380 ppm |
| Aug 25, 2015 18:07 | 380 ppm |
| Aug 17, 2015 07:55 | 420 ppm |
| Aug 10, 2015 06:38 | 400 ppm |
| Aug 3, 2015 05:14 | 400 ppm |
| Jul 27, 2015 04:54 | 400 ppm |
| Jul 13, 2015 04:26 | 400 ppm |
| Jul 7, 2015 02:43 | 410 ppm |
| Jul 2, 2015 02:10 | 320 ppm |
| Jun 29, 2015 23:00 | 200 ppm |