| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.58 | 4.2 | 3.05 |
| 2024 | 3.05 | 4.31 | 2.31 |
| 2023 | 2.9 | 3.99 | 2.29 |
| 2022 | 2.62 | 3.27 | 2.09 |
| 2021 | 2.07 | 2.68 | 1.56 |
| 2020 | 2.62 | 3.42 | 1.99 |
| 2019 | 2.98 | 4.55 | 2.12 |
| 2018 | 3.21 | 4.31 | 2.66 |
| 2017 | 5.88 | 8.71 | 4.13 |
| 2016 | 7.44 | 8.62 | 5.62 |
| 2015 | 7.29 | 13.15 | 4.48 |
| 2014 | 4.22 | 5.79 | 3.23 |
| 2013 | 3.73 | 4.59 | 3.16 |
| 2012 | 3.63 | 4.7 | 2.21 |
| 2011 | 4.2 | 5.64 | 2.49 |
| 2010 | 5.52 | 7.11 | 4.18 |
| 2009 | 5.53 | 8.15 | 3.71 |
| 2008 | 12.28 | 24.68 | 2.77 |
| 2007 | 12.24 | 24.68 | 3.59 |
| 2006 | 3.62 | 5.01 | 2.32 |
| 2005 | 2.29 | 3.71 | 1.28 |
| 2004 | 2.01 | 2.43 | 1.54 |
| 2003 | 2.53 | 3.44 | 1.57 |
| 2002 | 3.21 | 3.87 | 2.13 |
| 2001 | 3.99 | 5.13 | 2.71 |
| 2000 | 4.15 | 5.12 | 3.01 |
| 1999 | 3.63 | 4.16 | 2.91 |
| 1998 | 5.07 | 7.23 | 3.09 |
| 1997 | 3.89 | 6.92 | 2.48 |