| Year | Value (SE) |
|---|---|
| 2004 | 0.7820 (0.0577) |
| 2010 | 0.6320 (0.0995) |
| 2011 | 1.0340 (0.0851) |
| 2012 | 0.9360 (0.0550) |
| 2013 | 1.0270 (0.1424) |
| 2014 | 0.8380 (0.0729) |
| 2015 | 1.0090 (0.3186) |
| 2016 | 0.8100 (0.0350) |
| 2019 | 0.9290 (0.0971) |
| 2020 | 1.1350 (0.2568) |
| 2022 | 1.0680 (0.2670) |
| 2023 | 0.8880 (0.1348) |
