| 2024 | 0.06 | 0.1 | — | 60.8% |
| 2023 | 0.05 | 0.09 | — | 58.8% |
| 2022 | 0.07 | 0.1 | — | 67% |
| 2021 | 0.07 | 0.11 | — | 64.3% |
| 2020 | 0.07 | 0.1 | — | 68.7% |
| 2019 | 0.06 | 0.1 | — | 66% |
| 2018 | 0.06 | 0.09 | — | 69% |
| 2017 | 0.06 | 0.09 | — | 68.7% |
| 2016 | 0.07 | 0.1 | — | 71.8% |
| 2015 | 0.06 | 0.09 | — | 69.1% |
| 2014 | 0.06 | 0.08 | — | 69.4% |
| 2013 | 0.06 | 0.09 | — | 73.1% |
| 2012 | 0.07 | 0.09 | — | 73.5% |
| 2011 | 0.06 | 0.09 | — | 69.9% |
| 2010 | 0.07 | 0.09 | — | 73.7% |
| 2009 | 0.07 | 0.09 | — | 72.3% |
| 2008 | 0.06 | 0.08 | — | 72.8% |