| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.43 | 3.71 | 2.98 |
| 2024 | 3.52 | 4.31 | 3.04 |
| 2023 | 4.13 | 4.78 | 3.39 |
| 2022 | 4.89 | 6.65 | 3.38 |
| 2021 | 5.34 | 7.02 | 3.99 |
| 2020 | 3.65 | 6.16 | 2.54 |
| 2019 | 2.72 | 3.11 | 2.33 |
| 2018 | 2.78 | 3.43 | 2.3 |
| 2017 | 3.64 | 4.69 | 3 |
| 2016 | 3.74 | 4.56 | 3.05 |
| 2015 | 6.52 | 10.97 | 4.23 |
| 2014 | 2.74 | 4.46 | 1.93 |
| 2013 | 2.5 | 3.42 | 2.06 |
| 2012 | 2.08 | 2.51 | 1.81 |
| 2011 | 2.8 | 3.51 | 1.93 |
| 2010 | 3.46 | 4.4 | 2.49 |
| 2009 | 3.36 | 4.75 | 1.71 |
| 2008 | 6.17 | 21.43 | 1.2 |
| 2007 | 8.3 | 12.59 | 3.74 |
| 2006 | 2.51 | 3.92 | 1.36 |
| 2005 | 1.05 | 1.51 | 0.57 |
| 2004 | 1.12 | 1.47 | 0.88 |
| 2003 | 1.37 | 1.64 | 1.15 |
| 2002 | 1.7 | 1.95 | 1.29 |
| 2001 | 2.29 | 2.74 | 1.7 |
| 2000 | 4.09 | 5.23 | 3.53 |
| 1999 | 6.27 | 9.55 | 3.32 |
| 1998 | 4.68 | 6.74 | 3.83 |