| Year | Value (SE) |
|---|---|
| 2000 | 0.6330 (0.0295) |
| 2006 | 0.6850 (0.0341) |
| 2008 | 0.9630 (0.0313) |
| 2009 | 0.8990 (0.0255) |
| 2010 | 0.9960 (0.0561) |
| 2011 | 0.9310 (0.0091) |
| 2012 | 1.1280 (0.3824) |
| 2013 | 0.8770 (0.0226) |
| 2014 | 0.9140 (0.0176) |
| 2016 | 0.9190 (0.0213) |
| 2017 | 0.9030 (0.0163) |
| 2018 | 0.8940 (0.0241) |
| 2019 | 0.7820 (0.0125) |
| 2020 | 0.9010 (0.0942) |
| 2021 | 0.3250 (0.0847) |
| 2022 | 0.6240 (0.1759) |
| 2023 | 0.8490 (0.2446) |
| 2024 | 0.8920 (0.0726) |
