| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.21 | 3.79 | 2.76 |
| 2024 | 2.51 | 4.33 | 1.69 |
| 2023 | 2.66 | 3.4 | 2.16 |
| 2022 | 2.72 | 4.23 | 2.2 |
| 2021 | 3.97 | 5.28 | 3.07 |
| 2020 | 6.64 | 10.03 | 4.37 |
| 2019 | 5.54 | 8.62 | 2.5 |
| 2018 | 2.32 | 4.01 | 1.4 |
| 2017 | 3.33 | 5.35 | 2.32 |
| 2016 | 3.8 | 5.75 | 2.73 |
| 2015 | 4.51 | 7.52 | 2.73 |
| 2014 | 3.27 | 4.16 | 2.26 |
| 2013 | 2.18 | 3 | 1.67 |
| 2012 | 1.89 | 2.51 | 1.42 |
| 2011 | 3.15 | 4.14 | 2.14 |
| 2010 | 4.89 | 7.16 | 3.42 |
| 2009 | 5.08 | 6.61 | 3.76 |
| 2008 | 4.37 | 6 | 2.82 |