Data Table
| Year | Value (SE) |
| 2000 | 0.6595 (0.0886) |
| 2001 | 0.5330 (0.0247) |
| 2002 | 0.7986 (0.0145) |
| 2003 | 0.7507 (0.0300) |
| 2005 | 0.6748 (0.0505) |
| 2006 | 0.7067 (0.0248) |
| 2007 | 0.7955 (0.0177) |
| 2008 | 0.9532 (0.0952) |
| 2009 | 0.7368 (0.0473) |
| 2010 | 0.8073 (0.0738) |
| 2011 | 0.6835 (0.0519) |
| 2012 | 0.9480 (0.0509) |
| 2013 | 0.9522 (0.0797) |
| 2014 | 0.9155 (0.0762) |
| 2015 | 0.6324 (0.0745) |
| 2016 | 0.6906 (0.0433) |
| 2017 | 0.7464 (0.0526) |
| 2018 | 0.7905 (0.0786) |
| 2019 | 0.7831 (0.0789) |
| 2020 | 0.6460 (0.1279) |
| 2021 | 0.6270 (0.2881) |
| 2022 | 0.5405 (0.1548) |
| 2023 | 0.5529 (0.0906) |
| 2024 | 0.6635 (0.3040) |