| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.72 | 3.51 | 2.31 |
| 2024 | 1.8 | 3.85 | 0.77 |
| 2023 | 1.21 | 1.3 | 1.09 |
| 2022 | 1.23 | 1.6 | 0.98 |
| 2021 | 1.43 | 1.99 | 1.19 |
| 2020 | 1.62 | 2.14 | 1.42 |
| 2019 | 1.86 | 2.34 | 1.64 |
| 2018 | 2.22 | 2.86 | 1.51 |
| 2017 | 3.91 | 5.76 | 2.66 |
| 2016 | 4.48 | 5.73 | 3.59 |
| 2015 | 5.18 | 8.92 | 3.42 |
| 2014 | 4.91 | 8.69 | 3.58 |
| 2013 | 4.36 | 7.01 | 3.3 |
| 2012 | 4.78 | 6.82 | 3.63 |
| 2011 | 8.71 | 13.07 | 4.43 |
| 2010 | 10.89 | 16.23 | 6.27 |
| 2009 | 9.82 | 16.7 | 3.3 |
| 2008 | 4.68 | 7.39 | 2.46 |
| 2007 | 6.93 | 11.46 | 3.99 |
| 2006 | 3.84 | 5.64 | 2.53 |
| 2005 | 1.5 | 2.83 | 0.86 |
| 2004 | 2.16 | 4.06 | 1.36 |
| 2003 | 3.33 | 4.14 | 2.61 |
| 2002 | 4.14 | 5.56 | 2.47 |
| 2001 | 3.85 | 5.09 | 2.8 |
| 2000 | 3.64 | 5.07 | 2.43 |
| 1999 | 2.38 | 3.22 | 1.68 |
| 1998 | 1.82 | 2.42 | 1.4 |
| 1997 | 1.45 | 2.1 | 1.03 |