| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.68 | 2.98 | 2.33 |
| 2024 | 2.45 | 2.96 | 1.97 |
| 2023 | 3.3 | 4.03 | 2.6 |
| 2022 | 3.64 | 4.51 | 2.94 |
| 2021 | 3.3 | 5.6 | 2.48 |
| 2020 | 2.34 | 3.7 | 1.18 |
| 2019 | 1.58 | 2.02 | 1.35 |
| 2018 | 1.49 | 2.07 | 1.15 |
| 2017 | 2.71 | 3.84 | 1.8 |
| 2016 | 3.95 | 5.76 | 3.21 |
| 2015 | 4.82 | 7.69 | 2.56 |
| 2014 | 2.73 | 3.54 | 1.45 |
| 2013 | 1.46 | 1.84 | 1.17 |
| 2012 | 1.6 | 2.08 | 1.27 |
| 2011 | 2.77 | 4.28 | 1.6 |
| 2010 | 4.35 | 5.97 | 3.43 |
| 2009 | 3.4 | 4.58 | 2.07 |
| 2008 | 3.4 | 5.97 | 1.65 |
| 2007 | 5.04 | 9.07 | 1.96 |
| 2006 | 2.15 | 2.73 | 1.71 |
| 2005 | 2.09 | 2.41 | 1.39 |
| 2004 | 2.24 | 2.73 | 1.71 |
| 2003 | 2.51 | 2.86 | 2.26 |
| 2002 | 3.87 | 4.47 | 3.45 |
| 2001 | 5.02 | 6.16 | 3.66 |
| 2000 | 5.41 | 6.78 | 3.61 |
| 1999 | 3.85 | 4.74 | 2.96 |
| 1998 | 5.56 | 8.06 | 3.64 |
| 1997 | 6.15 | 8.68 | 3.32 |