| Year | Value (SE) |
|---|---|
| 2004 | 0.8369 (0.2645) |
| 2010 | 1.1287 (0.2851) |
| 2011 | 0.6394 (0.2436) |
| 2012 | 0.7904 (0.1288) |
| 2013 | 0.5271 (0.1277) |
| 2014 | 0.6657 (0.1425) |
| 2015 | 0.8165 (0.5191) |
| 2016 | 0.6471 (0.0823) |
| 2019 | 0.7565 (0.1815) |
| 2020 | 0.7371 (0.2470) |
| 2022 | 0.6720 (0.5440) |
| 2023 | 1.1480 (0.6441) |
