| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.24 | 4.99 | 3.64 |
| 2024 | 3.41 | 4.44 | 2.68 |
| 2023 | 3.46 | 5.39 | 2.13 |
| 2022 | 2.73 | 3.77 | 2.03 |
| 2021 | 3.62 | 4.52 | 2.95 |
| 2020 | 3.72 | 4.46 | 3.18 |
| 2019 | 2.87 | 3.92 | 2.15 |
| 2018 | 3.2 | 5.15 | 1.94 |
| 2017 | 4.38 | 5.26 | 3.62 |
| 2016 | 5.23 | 6.84 | 3.87 |
| 2015 | 5.02 | 8.36 | 3.07 |
| 2014 | 3.2 | 4.48 | 2.03 |
| 2013 | 2.22 | 2.73 | 1.84 |
| 2012 | 2.35 | 3.14 | 1.49 |
| 2011 | 4.27 | 5.96 | 2.2 |
| 2010 | 4.88 | 6.71 | 3.66 |
| 2009 | 3.61 | 6 | 1.93 |
| 2008 | 3.13 | 6.7 | 1.46 |
| 2007 | 4.47 | 6.17 | 2.34 |
| 2006 | 2.39 | 3.25 | 1.91 |
| 2005 | 2.7 | 4.03 | 1.73 |
| 2004 | 4.4 | 6.3 | 3.15 |
| 2003 | 6 | 7.69 | 4.05 |
| 2002 | 6.21 | 7.38 | 5.37 |
| 2001 | 9.77 | 15.36 | 6.87 |