| Date | Value |
|---|---|
| Feb 18, 2014 14:56 | 400 ppm |
| Jan 30, 2014 10:03 | 410 ppm |
| Jan 14, 2014 15:48 | 360 ppm |
| Jan 10, 2014 11:26 | 340 ppm |
| Jan 9, 2014 13:57 | 330 ppm |
| Jan 6, 2014 18:35 | 350 ppm |
| Dec 26, 2013 22:01 | 400 ppm |
| Dec 18, 2013 20:11 | 290 ppm |
| Dec 14, 2013 18:30 | 200 ppm |