| Year | Value (SE) |
|---|---|
| 2010 | 0.7520 (0.0641) |
| 2011 | 0.6150 (0.0547) |
| 2012 | 0.7460 (0.0827) |
| 2013 | 0.8220 (0.1097) |
| 2014 | 0.6300 (0.0907) |
| 2015 | 0.7490 (0.1448) |
| 2017 | 0.6170 (0.0742) |
| 2018 | 0.5440 (0.0926) |
| 2019 | 0.4750 (0.0944) |
| 2020 | 0.8090 (0.2170) |
| 2021 | 0.7600 (0.2912) |
| 2022 | 0.3360 (0.1340) |
| 2023 | 1.0860 (0.4562) |
