| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.92 | 4.58 | 3.42 |
| 2024 | 3.89 | 4.68 | 3.03 |
| 2023 | 4.56 | 6.31 | 3.3 |
| 2022 | 5.62 | 7.25 | 4.61 |
| 2021 | 2.06 | 2.69 | 0.99 |
| 2020 | 1.91 | 2.53 | 1.18 |
| 2019 | 1.76 | 2.6 | 1.25 |
| 2018 | 1.86 | 2.44 | 1.2 |
| 2017 | 2.97 | 3.71 | 2.3 |
| 2016 | 3.96 | 6.01 | 3 |
| 2015 | 5.94 | 10.06 | 3.69 |
| 2014 | 3.88 | 4.65 | 3.1 |
| 2013 | 3.32 | 4.28 | 2.35 |
| 2012 | 2.47 | 3.06 | 1.97 |
| 2011 | 3.7 | 6.74 | 2.12 |
| 2010 | 4.35 | 5.9 | 3.03 |
| 2009 | 2.43 | 3.22 | 1.46 |
| 2008 | 2.2 | 4.26 | 1.02 |
| 2007 | 3.14 | 4.77 | 1.56 |
| 2006 | 1.57 | 1.95 | 1.31 |
| 2005 | 1.63 | 1.94 | 1.27 |
| 2004 | 2.49 | 3.25 | 1.84 |
| 2003 | 3.01 | 3.84 | 2.23 |
| 2002 | 3.43 | 4.04 | 2.18 |
| 2001 | 4.4 | 5.3 | 3.02 |
| 2000 | 3.61 | 5 | 2.49 |
| 1999 | 2.71 | 3.98 | 1.92 |
| 1998 | 2.34 | 2.91 | 1.97 |
| 1997 | 2.9 | 4.2 | 2.04 |