| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.6 | 5.13 | 3.83 |
| 2024 | 3.93 | 6.5 | 2.84 |
| 2023 | 9.82 | 10.97 | 8.75 |
| 2022 | 7.52 | 11.95 | 1.43 |
| 2021 | 2 | 2.57 | 1.48 |
| 2020 | 2.25 | 3.11 | 1.62 |
| 2019 | 2 | 2.84 | 1.55 |
| 2018 | 2.42 | 3.13 | 1.76 |
| 2017 | 5.06 | 7.22 | 3.03 |
| 2016 | 5.71 | 7.32 | 3.54 |
| 2015 | 4.22 | 6.87 | 3.37 |
| 2014 | 3.73 | 5.21 | 3.15 |
| 2013 | 2.97 | 3.9 | 2.29 |
| 2012 | 2.4 | 3.29 | 1.83 |
| 2011 | 2.99 | 3.97 | 1.95 |
| 2010 | 3.68 | 4.79 | 2.85 |
| 2009 | 2.38 | 4.12 | 1.07 |
| 2008 | 3.01 | 7.93 | 0.75 |
| 2007 | 5.59 | 7.62 | 3.19 |
| 2006 | 2.5 | 3.64 | 1.81 |
| 2005 | 2.16 | 2.71 | 1.62 |