| Year | Value (SE) |
|---|---|
| 2012 | 0.7707 (0.0925) |
| 2013 | 0.5352 (0.0687) |
| 2014 | 0.8704 (0.0938) |
| 2015 | 0.5995 (0.1422) |
| 2016 | 0.7275 (0.0667) |
| 2017 | 0.8473 (0.0796) |
| 2018 | 0.6737 (0.0919) |
| 2019 | 0.9420 (0.1067) |
| 2020 | 0.8554 (0.2248) |
| 2021 | 0.4663 (0.2070) |
| 2022 | 1.4213 (0.6676) |
| 2023 | 0.7381 (0.1636) |
| 2024 | 0.3597 (0.1690) |
