| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.56 | 3.33 | 2.03 |
| 2024 | 2.31 | 2.84 | 1.98 |
| 2023 | 2.73 | 3.28 | 2.31 |
| 2022 | 2.34 | 3.6 | 1.64 |
| 2021 | 1.48 | 2.03 | 1.04 |
| 2020 | 1.16 | 1.4 | 0.95 |
| 2019 | 1.3 | 1.61 | 1.14 |
| 2018 | 1.54 | 2.03 | 1.19 |
| 2017 | 2.37 | 2.89 | 1.9 |
| 2016 | 2.77 | 3.25 | 2.41 |
| 2015 | 2.89 | 4.99 | 1.92 |
| 2014 | 1.81 | 2.68 | 1.4 |
| 2013 | 1.57 | 1.79 | 1.45 |
| 2012 | 1.86 | 2.3 | 1.39 |
| 2011 | 2.87 | 3.86 | 1.92 |
| 2010 | 4.16 | 8.73 | 2.22 |
| 2009 | 3.65 | 4.84 | 2.39 |
| 2008 | 5.13 | 9.46 | 2.01 |
| 2007 | 7.79 | 10.51 | 4.45 |
| 2006 | 3.47 | 5.01 | 2.46 |
| 2005 | 2.8 | 3.53 | 2.17 |
| 2004 | 3.65 | 6.41 | 2.61 |
| 2003 | 9.16 | 11.39 | 3.86 |
| 2002 | 8.94 | 10.38 | 7.41 |
| 2001 | 9.27 | 10.67 | 6.17 |