단위:PPM
| 년도 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 |
| RFsemi | 179 | 118 | 71.9 | 6.4 | 7.9 | 2.9 | 8.2 | 8.2 | 5.2 | 3.0 | 1 |
| AUK | 19 | 25 | 20.3 | 23.9 | 29.6 | 6.8 | 7.4 | 6.5 | 21.7 | 2.0 | 4.8 |
단위:PPM
| 년도 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 |
| RFsemi | 179 | 118 | 71.9 | 6.4 | 7.9 | 2.9 | 8.2 | 8.2 | 5.2 | 3.0 | 1 |
| AUK | 19 | 25 | 20.3 | 23.9 | 29.6 | 6.8 | 7.4 | 6.5 | 21.7 | 2.0 | 4.8 |