| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.25 | 3.92 | 2.86 |
| 2024 | 3.07 | 3.7 | 2.44 |
| 2023 | 4.12 | 5.47 | 3.18 |
| 2022 | 3.69 | 4.86 | 2.46 |
| 2021 | 3.73 | 5.23 | 3.14 |
| 2020 | 4.24 | 5.38 | 3.41 |
| 2019 | 3.55 | 4.65 | 2.15 |
| 2018 | 2.81 | 4.37 | 1.91 |
| 2017 | 3.78 | 4.69 | 3.15 |
| 2016 | 4.9 | 6.68 | 4.19 |
| 2015 | 8.38 | 15.65 | 4.57 |
| 2014 | 5.8 | 7.36 | 4.68 |
| 2013 | 5.82 | 7.41 | 4.51 |
| 2012 | 6.2 | 7.05 | 5.13 |
| 2011 | 8.8 | 13.2 | 6.72 |
| 2010 | 11.46 | 13.9 | 8.68 |
| 2009 | 6.91 | 10.91 | 3.97 |
| 2008 | 4.78 | 8.12 | 2.53 |
| 2007 | 6.95 | 8.61 | 5.53 |