| Year | Value (SE) |
|---|---|
| 2001 | 0.4910 (0.0669) |
| 2002 | 0.8160 (0.0793) |
| 2010 | 0.6090 (0.0717) |
| 2011 | 0.6800 (0.1082) |
| 2012 | 0.4730 (0.0976) |
| 2013 | 0.6760 (0.1240) |
| 2014 | 0.6180 (0.0925) |
| 2015 | 1.7870 (1.7809) |
| 2016 | 0.4850 (0.1102) |
| 2017 | 0.4600 (0.1131) |
| 2018 | 0.6680 (0.1529) |
| 2020 | 0.7820 (0.1904) |
| 2021 | 0.8260 (0.2580) |
| 2022 | 0.6070 (0.2862) |
| 2023 | 0.6280 (0.1438) |
