| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.13 | 3.56 | 2.84 |
| 2024 | 2.61 | 3.85 | 2.16 |
| 2023 | 3.39 | 4.65 | 2.61 |
| 2022 | 4.07 | 4.68 | 3.34 |
| 2021 | 3.48 | 4.61 | 2.68 |
| 2020 | 3.22 | 3.71 | 2.93 |
| 2019 | 7.32 | 9.19 | 5.61 |
| 2018 | 7.05 | 8.1 | 5.44 |
| 2017 | 7.39 | 12.23 | 1.87 |
| 2016 | 2.05 | 2.82 | 1.37 |
| 2015 | 2.83 | 5.43 | 1.65 |
| 2014 | 1.08 | 2.44 | 0.7 |
| 2013 | 1.1 | 1.74 | 0.75 |
| 2012 | 1.58 | 2.12 | 1.13 |
| 2011 | 3.11 | 4.74 | 1.57 |
| 2010 | 3.3 | 4.68 | 2.48 |
| 2009 | 2.84 | 3.38 | 1.94 |
| 2008 | 3.93 | 9.13 | 1.23 |
| 2007 | 5.59 | 7.64 | 2.44 |
| 2006 | 1.79 | 2.56 | 1.19 |
| 2005 | 1.43 | 2.02 | 0.98 |
| 2004 | 2.71 | 3.86 | 1.9 |
| 2003 | 3.72 | 4.43 | 3.06 |
| 2002 | 5.19 | 5.65 | 3.35 |
| 2001 | 4.98 | 5.83 | 3.87 |
| 2000 | 2.86 | 3.71 | 2.01 |
| 1999 | 2.25 | 3.09 | 1.7 |
| 1998 | 2.07 | 2.64 | 1.74 |
| 1997 | 2.36 | 3.47 | 1.81 |