| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.97 | 3.06 | 2.82 |
| 2024 | 3 | 3.82 | 2.25 |
| 2023 | 3.72 | 4.95 | 3.01 |
| 2022 | 4.34 | 5.22 | 3.43 |
| 2021 | 3.22 | 4.17 | 2.55 |
| 2020 | 3.7 | 4.6 | 2.8 |
| 2019 | 3.24 | 4.05 | 1.91 |
| 2018 | 2.67 | 4.14 | 1.67 |
| 2017 | 4.71 | 5.44 | 3.85 |
| 2016 | 4.99 | 6.96 | 3.38 |
| 2015 | 5.34 | 9.93 | 3.4 |
| 2014 | 4.43 | 6.05 | 3.67 |
| 2013 | 5.2 | 6.96 | 3.53 |
| 2012 | 3.47 | 4.06 | 2.9 |
| 2011 | 4.84 | 6.43 | 3.17 |
| 2010 | 4.82 | 7.46 | 2.92 |
| 2009 | 2.27 | 3.08 | 1.37 |
| 2008 | 2.43 | 4.22 | 1.05 |
| 2007 | 2.61 | 4.16 | 1.24 |
| 2006 | 1.55 | 1.98 | 1.18 |
| 2005 | 1.92 | 2.74 | 1.53 |
| 2004 | 2.88 | 5.63 | 1.81 |