| Year | Value (SE) |
|---|---|
| 2012 | 0.8643 (0.0200) |
| 2013 | 0.8482 (0.0468) |
| 2014 | 0.7953 (0.0416) |
| 2015 | 1.1445 (0.1573) |
| 2016 | 0.9377 (0.0372) |
| 2017 | 0.9123 (0.0241) |
| 2018 | 0.8702 (0.0365) |
| 2020 | 0.9210 (0.1848) |
| 2021 | 0.8320 (0.2310) |
| 2022 | 0.8599 (0.1770) |
| 2023 | 0.7824 (0.0435) |
| 2025 | 1.6270 (0.5884) |
