| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.97 | 3.62 | 2.64 |
| 2024 | 2.7 | 3.7 | 1.94 |
| 2023 | 3.51 | 3.91 | 2.93 |
| 2022 | 3.38 | 4.34 | 2.77 |
| 2021 | 3.71 | 4.47 | 3.38 |
| 2020 | 4.06 | 4.87 | 3 |
| 2019 | 3.13 | 3.74 | 2.77 |
| 2018 | 3.84 | 5.18 | 2.81 |
| 2017 | 5.72 | 7.34 | 4.53 |
| 2016 | 7.91 | 11.5 | 6.02 |
| 2015 | 8.03 | 13.78 | 4.54 |
| 2014 | 4.92 | 7.75 | 3.63 |
| 2013 | 4.27 | 5.03 | 3.74 |
| 2012 | 3.93 | 5 | 3.28 |
| 2011 | 5.61 | 7.45 | 3.48 |
| 2010 | 6.95 | 10.47 | 4.5 |
| 2009 | 6.63 | 11.09 | 2.6 |
| 2008 | 5.05 | 13.13 | 1.77 |
| 2007 | 12.21 | 26.88 | 2.19 |
| 2006 | 2.24 | 3.43 | 1.66 |
| 2005 | 1.82 | 2.29 | 1.51 |
| 2004 | 3.05 | 5.7 | 1.76 |