| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.91 | 3.15 | 1.64 |
| 2024 | 1.77 | 2.6 | 1.33 |
| 2023 | 2.51 | 2.9 | 1.99 |
| 2022 | 2.88 | 4.25 | 2.34 |
| 2021 | 2.9 | 4.31 | 2.33 |
| 2020 | 2.64 | 3.21 | 2.25 |
| 2019 | 2.9 | 4.07 | 2.32 |
| 2018 | 3.97 | 6.53 | 2.6 |
| 2017 | 7.21 | 9.79 | 5.02 |
| 2016 | 6.83 | 12.57 | 4.99 |
| 2015 | 6.32 | 10.99 | 4.23 |
| 2014 | 4.9 | 6.54 | 3.12 |
| 2013 | 3.91 | 5.83 | 3.1 |
| 2012 | 3.47 | 4.27 | 2.49 |
| 2011 | 4.3 | 5.08 | 2.63 |
| 2010 | 4.84 | 6.3 | 3.49 |
| 2009 | 3.36 | 5.67 | 1.42 |
| 2008 | 2.68 | 4.86 | 1.06 |
| 2007 | 3.84 | 5.62 | 1.39 |
| 2006 | 1.41 | 1.72 | 1.26 |
| 2005 | 1.53 | 2.06 | 1.14 |
| 2004 | 2.97 | 4.74 | 2.01 |
| 2003 | 3.86 | 5.25 | 3.11 |
| 2002 | 7.53 | 11.41 | 6.31 |
| 2001 | 11.53 | 13.88 | 7.55 |
| 2000 | 5.86 | 11.35 | 3.09 |
| 1999 | 2.86 | 4.16 | 2.18 |
| 1998 | 2.99 | 4.45 | 2.12 |
| 1997 | 4.31 | 7.44 | 2.82 |