| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.72 | 1.92 | 1.49 |
| 2024 | 1.34 | 2.05 | 1.01 |
| 2023 | 1.51 | 1.84 | 1.18 |
| 2022 | 1.27 | 1.77 | 0.92 |
| 2021 | 1.17 | 1.43 | 1 |
| 2020 | 1.01 | 1.76 | 0.58 |
| 2019 | 0.89 | 1.34 | 0.64 |
| 2018 | 0.97 | 1.85 | 0.71 |
| 2017 | 2.22 | 3 | 1.73 |
| 2016 | 2.51 | 3.23 | 2.07 |
| 2015 | 4.1 | 5.83 | 2.82 |
| 2014 | 3.77 | 4.26 | 2.97 |
| 2013 | 3.81 | 4.95 | 2.94 |
| 2012 | 5.2 | 6.94 | 3.49 |
| 2011 | 7.59 | 9.5 | 5.89 |
| 2010 | 8.6 | 12.45 | 6.22 |
| 2009 | 4.92 | 6.72 | 4 |
| 2008 | 9.76 | 25.61 | 3.25 |
| 2007 | 13.7 | 16.79 | 10.92 |