| Year | Value (SE) |
|---|---|
| 2000 | 0.5471 (0.1292) |
| 2006 | 0.9524 (0.1191) |
| 2008 | 0.7601 (0.0478) |
| 2009 | 0.7856 (0.0593) |
| 2010 | 0.7385 (0.0580) |
| 2011 | 0.8268 (0.0378) |
| 2012 | 0.4427 (0.1687) |
| 2013 | 0.4401 (0.1009) |
| 2014 | 0.6164 (0.1758) |
| 2016 | 0.2234 (0.1276) |
| 2017 | 0.5458 (0.1026) |
| 2018 | 0.6523 (0.0490) |
| 2019 | 0.4965 (0.0412) |
| 2020 | 0.3448 (0.0576) |
| 2021 | 0.9958 (0.3861) |
| 2022 | 0.3052 (0.0540) |
| 2023 | 0.1503 (0.0528) |
| 2024 | 0.2602 (0.0521) |
