| Year | Value (SE) |
|---|---|
| 2012 | 0.8869 (0.1091) |
| 2013 | 0.8647 (0.1628) |
| 2014 | 0.7625 (0.1690) |
| 2015 | 0.9242 (0.2821) |
| 2016 | 0.6855 (0.0891) |
| 2017 | 0.9790 (0.1067) |
| 2018 | 0.8516 (0.1861) |
| 2020 | 1.2211 (0.5830) |
| 2021 | 0.3812 (0.4032) |
| 2022 | 1.0887 (0.6219) |
| 2023 | 0.9951 (0.3559) |
| 2025 | 0.8174 (0.5788) |
