| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 15.72 | 20.82 | 10.83 |
| 2024 | 12.87 | 28.79 | 5.99 |
| 2023 | 9.82 | 11.58 | 8.44 |
| 2022 | 8.35 | 15.45 | 3.7 |
| 2021 | 5.36 | 10.05 | 2.54 |
| 2020 | 5.48 | 9.31 | 2.74 |
| 2019 | 4.13 | 6.54 | 2.72 |
| 2018 | 4.38 | 6.09 | 2.63 |
| 2017 | 7.03 | 12.51 | 4.28 |
| 2016 | 5.89 | 11.37 | 3.49 |
| 2015 | 7.98 | 20.89 | 3.26 |
| 2014 | 6.42 | 10.29 | 3.61 |
| 2013 | 5.49 | 7.25 | 3.57 |
| 2012 | 6.29 | 8.26 | 4.77 |
| 2011 | 10.36 | 17.35 | 6.92 |
| 2010 | 5.89 | 7.89 | 4.57 |
| 2009 | 3.87 | 5.3 | 3.07 |
| 2008 | 4.29 | 6.06 | 2.51 |
| 2007 | 4.61 | 7.01 | 2.21 |
| 2006 | 1.83 | 2.42 | 1.22 |
| 2005 | 1.5 | 2.06 | 0.99 |
| 2004 | 2.37 | 3.15 | 1.92 |
| 2003 | 2.79 | 3.34 | 2.05 |
| 2002 | 3.9 | 4.72 | 2.83 |
| 2001 | 5.65 | 7.27 | 3.97 |
| 2000 | 4.97 | 6.46 | 3.39 |
| 1999 | 3.19 | 4.64 | 2.06 |
| 1998 | 2.78 | 3.48 | 2.14 |
| 1997 | 3.69 | 4.89 | 2.72 |