| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5 | 6.56 | 4.08 |
| 2024 | 3.55 | 8.23 | 2.55 |
| 2023 | 4.01 | 5.94 | 3.32 |
| 2022 | 3.24 | 3.9 | 2.48 |
| 2021 | 2.69 | 3.31 | 1.86 |
| 2020 | 2.81 | 4.51 | 2.18 |
| 2019 | 2.14 | 3.05 | 1.2 |
| 2018 | 2 | 2.95 | 1.18 |
| 2017 | 4.01 | 5.15 | 2.95 |
| 2016 | 5.1 | 6.55 | 3.36 |
| 2015 | 6.87 | 18.51 | 3.24 |
| 2014 | 2.68 | 3.89 | 1.79 |
| 2013 | 1.81 | 2.22 | 1.53 |
| 2012 | 1.77 | 2.02 | 1.6 |
| 2011 | 2.41 | 2.98 | 1.72 |
| 2010 | 2.84 | 3.58 | 2.11 |
| 2009 | 2.59 | 3.41 | 1.72 |
| 2008 | 3.41 | 7.26 | 1.16 |
| 2007 | 5.76 | 10.75 | 3.83 |
| 2006 | 4.33 | 4.33 | 4.33 |