| Year | Value (SE) |
|---|---|
| 2012 | 0.8491 (0.1059) |
| 2013 | 0.7734 (0.1518) |
| 2014 | 0.7620 (0.1725) |
| 2015 | 0.9914 (0.3327) |
| 2016 | 0.6245 (0.0852) |
| 2017 | 0.8901 (0.0996) |
| 2018 | 0.7290 (0.1617) |
| 2020 | 0.7745 (0.4010) |
| 2021 | 1.2812 (1.4017) |
| 2022 | 0.7650 (0.4647) |
| 2023 | 0.9009 (0.3257) |
| 2025 | 0.9268 (0.7368) |
