| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.48 | 3.01 | 2.02 |
| 2024 | 1.79 | 2.54 | 1.35 |
| 2023 | 2.75 | 3.33 | 2.13 |
| 2022 | 4.75 | 6.74 | 2.84 |
| 2021 | 4.35 | 6.41 | 3.61 |
| 2020 | 4.14 | 4.85 | 3.1 |
| 2019 | 5.97 | 12.4 | 3.04 |
| 2018 | 9.06 | 15.33 | 2.98 |
| 2017 | 4.89 | 7.27 | 3.18 |
| 2016 | 5.68 | 7.57 | 4.26 |
| 2015 | 7.23 | 13.04 | 4.02 |
| 2014 | 5.44 | 7.24 | 3.24 |
| 2013 | 3.47 | 4.23 | 2.62 |
| 2012 | 4.54 | 6.89 | 3.29 |
| 2011 | 4.81 | 6.52 | 3.74 |
| 2010 | 4.93 | 6.13 | 3.56 |
| 2009 | 4.16 | 5.61 | 1.93 |
| 2008 | 3.49 | 6.46 | 1.3 |
| 2007 | 4.71 | 6.85 | 1.82 |
| 2006 | 1.89 | 2.37 | 1.55 |
| 2005 | 1.82 | 2.56 | 1.52 |
| 2004 | 3.1 | 4.28 | 2.38 |
| 2003 | 4.05 | 5.18 | 2.86 |
| 2002 | 7.09 | 7.99 | 6.05 |
| 2001 | 8.2 | 9.96 | 7.09 |
| 2000 | 12.61 | 23.01 | 6.99 |
| 1999 | 6.71 | 9.46 | 4.73 |
| 1998 | 4 | 6 | 2.05 |
| 1997 | 2.34 | 3.19 | 1.81 |