| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.22 | 3.74 | 2.85 |
| 2024 | 3.47 | 4.16 | 2.59 |
| 2023 | 4.89 | 6.4 | 3.32 |
| 2022 | 5.36 | 6.18 | 4.29 |
| 2021 | 5.82 | 7.28 | 4.75 |
| 2020 | 4.54 | 6.89 | 2.56 |
| 2019 | 3.31 | 3.91 | 2.39 |
| 2018 | 2.99 | 4.28 | 2.1 |
| 2017 | 2.6 | 3.13 | 2.31 |
| 2016 | 2.37 | 2.59 | 2.17 |
| 2015 | 3.37 | 4.87 | 2.51 |
| 2014 | 3.74 | 4.54 | 3.29 |
| 2013 | 4.11 | 4.91 | 3.48 |
| 2012 | 3.95 | 4.73 | 3.19 |
| 2011 | 4.59 | 5.25 | 3.91 |
| 2010 | 5.77 | 7.4 | 4.82 |
| 2009 | 5.51 | 7.22 | 3.91 |
| 2008 | 5.62 | 9.77 | 3.38 |
| 2007 | 6.48 | 10.67 | 3.69 |
| 2006 | 2.92 | 3.84 | 2.17 |
| 2005 | 1.63 | 2.23 | 1.02 |
| 2004 | 2.02 | 3.02 | 1.58 |
| 2003 | 2.38 | 2.58 | 1.95 |
| 2002 | 2.59 | 3.09 | 2.31 |
| 2001 | 3.43 | 4.23 | 2.6 |
| 2000 | 2.75 | 3.42 | 2.28 |
| 1999 | 1.99 | 3.01 | 1.33 |
| 1998 | 1.6 | 1.97 | 1.34 |
| 1997 | 1.9 | 2.49 | 1.53 |