Data Table
| Year | Value (SE) |
| 2000 | 0.7869 (0.1055) |
| 2001 | 0.5546 (0.0257) |
| 2002 | 0.8469 (0.0150) |
| 2003 | 0.8160 (0.0316) |
| 2005 | 0.7126 (0.0533) |
| 2006 | 0.8077 (0.0280) |
| 2007 | 0.8499 (0.0182) |
| 2008 | 0.9868 (0.0979) |
| 2009 | 0.7202 (0.0461) |
| 2010 | 0.8163 (0.0718) |
| 2011 | 0.7256 (0.0547) |
| 2012 | 1.0664 (0.0565) |
| 2013 | 0.9052 (0.0744) |
| 2014 | 0.8661 (0.0716) |
| 2015 | 0.5905 (0.0674) |
| 2016 | 0.6872 (0.0431) |
| 2017 | 0.8167 (0.0563) |
| 2018 | 0.8192 (0.0807) |
| 2019 | 0.8512 (0.0842) |
| 2020 | 0.7333 (0.1452) |
| 2021 | 0.8039 (0.3696) |
| 2022 | 0.8367 (0.2399) |
| 2023 | 0.6003 (0.0984) |
| 2024 | 0.7532 (0.3448) |