| Year | Value (SE) |
|---|---|
| 2012 | 0.7416 (0.0905) |
| 2013 | 0.4911 (0.0658) |
| 2014 | 0.8264 (0.0917) |
| 2015 | 0.7961 (0.2018) |
| 2016 | 0.6492 (0.0627) |
| 2017 | 0.7355 (0.0714) |
| 2018 | 0.6589 (0.0911) |
| 2019 | 0.9484 (0.1093) |
| 2020 | 0.7322 (0.2020) |
| 2021 | 0.7224 (0.3378) |
| 2022 | 1.0747 (0.5296) |
| 2023 | 0.7573 (0.1728) |
| 2024 | 0.5361 (0.2691) |
