| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.78 | 4.28 | 3.4 |
| 2024 | 4.99 | 6.86 | 3.27 |
| 2023 | 7.42 | 9.26 | 5.63 |
| 2022 | 7.01 | 8.45 | 5.35 |
| 2021 | 10.38 | 15.96 | 6.94 |
| 2020 | 10.33 | 15.22 | 5.83 |
| 2019 | 6.48 | 8.14 | 3.57 |
| 2018 | 5.36 | 7.17 | 3.77 |
| 2017 | 4.75 | 6.14 | 3.86 |
| 2016 | 4.1 | 5.03 | 2.89 |
| 2015 | 4.03 | 5.36 | 2.93 |
| 2014 | 2.98 | 4.7 | 2.15 |
| 2013 | 3.59 | 6.01 | 2.37 |
| 2012 | 7.09 | 10.01 | 3.93 |
| 2011 | 16.18 | 22.67 | 7.91 |
| 2010 | 14.85 | 24.55 | 10.29 |
| 2009 | 5.62 | 11.53 | 2.3 |
| 2008 | 3.79 | 7.73 | 1.65 |
| 2007 | 4.65 | 9.04 | 2.06 |
| 2006 | 1.64 | 2.44 | 1.18 |
| 2005 | 0.79 | 1.19 | 0.46 |
| 2004 | 1.17 | 1.59 | 0.82 |
| 2003 | 1.5 | 1.97 | 1.14 |
| 2002 | 2.33 | 2.59 | 1.95 |
| 2001 | 3.37 | 4.68 | 2.2 |
| 2000 | 3.49 | 4.73 | 2.53 |
| 1999 | 2.84 | 3.84 | 2.32 |
| 1998 | 4.34 | 6.48 | 2.87 |
| 1997 | 5.57 | 6.94 | 4.4 |