| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.26 | 2.48 | 2.05 |
| 2024 | 2.03 | 2.67 | 1.23 |
| 2023 | 2.42 | 2.82 | 2.09 |
| 2022 | 2.33 | 4.01 | 1.6 |
| 2021 | 1.88 | 2.45 | 1.54 |
| 2020 | 2.02 | 2.56 | 1.77 |
| 2019 | 2.38 | 2.94 | 1.78 |
| 2018 | 2.33 | 3.22 | 1.54 |
| 2017 | 3.16 | 3.91 | 2.6 |
| 2016 | 4.92 | 7.36 | 3.35 |
| 2015 | 4.56 | 7.91 | 3.18 |
| 2014 | 3.52 | 5.58 | 2.51 |
| 2013 | 4.24 | 4.93 | 3.57 |
| 2012 | 4.44 | 5.54 | 3.61 |
| 2011 | 6.14 | 7.43 | 3.93 |
| 2010 | 7.45 | 11.36 | 4.97 |
| 2009 | 7.25 | 12.57 | 4.22 |
| 2008 | 5.84 | 9.93 | 3.32 |
| 2007 | 6.94 | 11.48 | 2.87 |
| 2006 | 2.83 | 3.8 | 2.01 |
| 2005 | 2.17 | 2.89 | 1.65 |
| 2004 | 3.37 | 4.46 | 2.43 |
| 2003 | 4.18 | 5.46 | 3.1 |
| 2002 | 7.36 | 8.98 | 6.01 |
| 2001 | 10.2 | 12.95 | 4.8 |
| 2000 | 6.28 | 8.44 | 4.75 |
| 1999 | 4.4 | 5.92 | 3.43 |
| 1998 | 4.33 | 6.71 | 2.73 |
| 1997 | 4.8 | 6.8 | 3.72 |