| Year | Value (SE) |
|---|---|
| 2004 | 0.6186 (0.0662) |
| 2010 | 0.7439 (0.1286) |
| 2011 | 0.7362 (0.1219) |
| 2012 | 0.9089 (0.0922) |
| 2013 | 0.6922 (0.1138) |
| 2014 | 0.7726 (0.1019) |
| 2015 | 0.7164 (0.2614) |
| 2016 | 0.7290 (0.0492) |
| 2019 | 0.6401 (0.1046) |
| 2020 | 0.9296 (0.2824) |
| 2022 | 1.9993 (1.4597) |
| 2023 | 1.1624 (0.5169) |
