| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.02 | 3.71 | 2.62 |
| 2024 | 2.52 | 3.65 | 1.7 |
| 2023 | 2.32 | 3.38 | 1.73 |
| 2022 | 2.46 | 3.33 | 2.03 |
| 2021 | 2.3 | 2.78 | 1.91 |
| 2020 | 2.46 | 3.25 | 2.19 |
| 2019 | 2.71 | 4.26 | 2.3 |
| 2018 | 2.7 | 3.71 | 1.91 |
| 2017 | 4.25 | 5.62 | 3.37 |
| 2016 | 4.38 | 5.42 | 3.41 |
| 2015 | 5.26 | 8.68 | 3.59 |
| 2014 | 3.76 | 5.14 | 2.93 |
| 2013 | 3.13 | 3.88 | 2.63 |
| 2012 | 3.08 | 4.03 | 2.42 |
| 2011 | 5.16 | 6.45 | 3.36 |
| 2010 | 5.2 | 6.57 | 3.86 |
| 2009 | 4.64 | 7.12 | 2.74 |
| 2008 | 4.71 | 11.64 | 1.99 |
| 2007 | 9.28 | 13.59 | 7.31 |
| 2006 | 4.8 | 7.36 | 2.69 |
| 2005 | 4.5 | 4.97 | 3.21 |
| 2004 | 5.46 | 6.69 | 4.7 |
| 2003 | 6.81 | 7.42 | 6.3 |
| 2002 | 7.72 | 8.62 | 7.05 |
| 2001 | 8.88 | 10.99 | 6.52 |
| 2000 | 5.71 | 7.32 | 3.29 |
| 1999 | 3.49 | 4.16 | 2.79 |
| 1998 | 7.32 | 9.75 | 4.33 |
| 1997 | 7.96 | 11.94 | 4.02 |