| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.7 | 7.48 | 6.1 |
| 2024 | 5.84 | 8.53 | 4.54 |
| 2023 | 7.58 | 9.58 | 5.67 |
| 2022 | 4.05 | 8.62 | 3.14 |
| 2021 | 5.44 | 9.05 | 3.41 |
| 2020 | 3.22 | 5.55 | 1.66 |
| 2019 | 2.67 | 4.83 | 1.97 |
| 2018 | 2.53 | 3.69 | 1.56 |
| 2017 | 3.85 | 4.51 | 3.09 |
| 2016 | 4.01 | 4.9 | 3.18 |
| 2015 | 4.49 | 8.55 | 2.92 |
| 2014 | 2.24 | 3.33 | 1.74 |
| 2013 | 1.79 | 2.31 | 1.37 |
| 2012 | 1.68 | 2.09 | 1.21 |
| 2011 | 3.99 | 8.6 | 1.43 |
| 2010 | 5.04 | 6.7 | 3.58 |
| 2009 | 4.09 | 5.51 | 2.11 |
| 2008 | 3.65 | 6.07 | 1.59 |
| 2007 | 4.92 | 6.78 | 2.79 |
| 2006 | 2.58 | 3.07 | 2.02 |
| 2005 | 4.03 | 6.12 | 2.29 |
| 2004 | 7.46 | 11.91 | 5.53 |