| Year | Value (SE) |
|---|---|
| 2004 | 0.7910 (0.0806) |
| 2010 | 1.1770 (0.1721) |
| 2011 | 0.7120 (0.1146) |
| 2012 | 0.9710 (0.0940) |
| 2013 | 0.6740 (0.1007) |
| 2014 | 0.9220 (0.1143) |
| 2015 | 0.7100 (0.2368) |
| 2016 | 0.9000 (0.0568) |
| 2019 | 0.6890 (0.1049) |
| 2020 | 0.8190 (0.2323) |
| 2022 | 1.8720 (1.3392) |
| 2023 | 1.3090 (0.5709) |
