| Date | Value |
|---|---|
| Jun 30, 2013 12:01 | 0.00 ppm |
| Jun 16, 2013 11:29 | 0.00 ppm |
| May 29, 2013 19:43 | 0.00 ppm |
| May 27, 2013 17:37 | 0.05 ppm |
| May 23, 2013 16:48 | 0.05 ppm |
| May 19, 2013 19:56 | 0.05 ppm |
| May 17, 2013 16:52 | 0.05 ppm |
| May 14, 2013 18:59 | 0.00 ppm |
| May 12, 2013 16:14 | 0.05 ppm |
| May 9, 2013 19:26 | 0.00 ppm |
| May 6, 2013 16:47 | 0.00 ppm |
| May 5, 2013 16:01 | 0.05 ppm |