| Date | Value |
|---|---|
| Feb 4, 2018 18:51 | 0.02 ppm |
| Feb 3, 2018 18:18 | 0.01 ppm |
| Feb 2, 2018 22:48 | 0.04 ppm |
| Feb 2, 2018 18:22 | 0.07 ppm |
| Jan 30, 2018 18:15 | 0.00 ppm |
| Jan 29, 2018 18:52 | 0.01 ppm |
| Jan 28, 2018 22:27 | 0.01 ppm |
| Jan 27, 2018 19:22 | 0.00 ppm |
| Jan 22, 2018 20:56 | 0.50 ppm |