| Year | Value (SE) |
|---|---|
| 2012 | 0.7630 (0.0925) |
| 2013 | 0.5903 (0.0770) |
| 2014 | 0.8626 (0.0945) |
| 2015 | 0.7692 (0.1924) |
| 2016 | 0.6584 (0.0635) |
| 2017 | 0.7693 (0.0740) |
| 2018 | 0.6582 (0.0906) |
| 2019 | 0.9778 (0.1124) |
| 2020 | 0.8349 (0.2304) |
| 2021 | 0.7349 (0.3438) |
| 2022 | 1.1797 (0.5821) |
| 2023 | 0.7543 (0.1721) |
| 2024 | 0.5125 (0.2573) |
