| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.22 | 5.22 | 3.79 |
| 2024 | 4.22 | 4.84 | 3.74 |
| 2023 | 4.96 | 5.78 | 4.11 |
| 2022 | 5.11 | 6.04 | 4.58 |
| 2021 | 5.53 | 7.42 | 4.65 |
| 2020 | 5.35 | 6.83 | 4.53 |
| 2019 | 7.05 | 10.87 | 5.6 |
| 2018 | 6.81 | 10.55 | 5.6 |
| 2017 | 6.08 | 8.28 | 3.33 |
| 2016 | 3.04 | 4.59 | 2.29 |
| 2015 | 8.12 | 26.9 | 3.7 |
| 2014 | 3.21 | 7.08 | 2.01 |
| 2013 | 2.87 | 4.1 | 2.11 |
| 2012 | 2.99 | 3.44 | 2.44 |
| 2011 | 4.58 | 6.87 | 3.14 |
| 2010 | 4.78 | 7.02 | 3.82 |
| 2009 | 3.68 | 5.49 | 1.79 |
| 2008 | 2.72 | 5.41 | 1.37 |
| 2007 | 4.82 | 7.75 | 1.86 |
| 2006 | 1.8 | 2.28 | 1.29 |
| 2005 | 0.89 | 1.31 | 0.53 |
| 2004 | 1.47 | 1.85 | 1.19 |
| 2003 | 1.42 | 1.67 | 1.23 |
| 2002 | 1.54 | 1.75 | 1.13 |
| 2001 | 2 | 2.73 | 1.46 |
| 2000 | 1.83 | 2.17 | 1.56 |
| 1999 | 1.42 | 1.99 | 0.91 |
| 1998 | 1.37 | 1.71 | 1.08 |
| 1997 | 1.7 | 2.31 | 1.17 |