| Year | Value (SE) |
|---|---|
| 2011 | 0.8877 (0.2197) |
| 2012 | 0.6677 (0.1554) |
| 2013 | 0.9205 (0.2304) |
| 2014 | 0.4358 (0.1236) |
| 2015 | 0.4611 (0.1298) |
| 2016 | 0.3554 (0.0839) |
| 2017 | 0.6137 (0.1509) |
| 2018 | 0.5376 (0.1696) |
| 2019 | 0.5157 (0.1847) |
| 2020 | 0.6914 (0.2765) |
| 2021 | 0.9485 (0.7776) |
| 2022 | 1.3245 (0.7149) |
| 2023 | 0.5841 (0.2661) |
