| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.86 | 2.09 | 1.77 |
| 2024 | 1.8 | 2.54 | 1.42 |
| 2023 | 2.35 | 2.81 | 1.97 |
| 2022 | 2.26 | 2.72 | 1.87 |
| 2021 | 2.63 | 3.95 | 2.13 |
| 2020 | 1.68 | 4.34 | 1.11 |
| 2019 | 1.42 | 1.72 | 1.14 |
| 2018 | 1.68 | 2.48 | 1.11 |
| 2017 | 2.85 | 3.49 | 2.31 |
| 2016 | 2.72 | 3.35 | 2.27 |
| 2015 | 3.27 | 5.94 | 2.24 |
| 2014 | 2.54 | 3.68 | 2 |
| 2013 | 2.9 | 3.52 | 2.31 |
| 2012 | 4.1 | 5.29 | 2.65 |
| 2011 | 4.44 | 5.36 | 3.39 |
| 2010 | 6.11 | 8.39 | 4.34 |
| 2009 | 5.98 | 7.08 | 4.46 |
| 2008 | 7.16 | 14.07 | 3.93 |
| 2007 | 12.86 | 17.11 | 7.04 |
| 2006 | 6.47 | 8.44 | 4.52 |
| 2005 | 5.73 | 7.24 | 4.43 |
| 2004 | 6.88 | 14.33 | 4.65 |
| 2003 | 10.72 | 12.47 | 6.39 |
| 2002 | 5.84 | 6.88 | 3.9 |
| 2001 | 5.99 | 7.48 | 4.61 |
| 2000 | 9.58 | 12.83 | 5.88 |
| 1999 | 5.91 | 7.22 | 4.71 |
| 1998 | 5.97 | 7.95 | 3.5 |
| 1997 | 4.05 | 5.85 | 3.1 |