| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.05 | 4.75 | 3.49 |
| 2024 | 2.77 | 6.24 | 1.89 |
| 2023 | 2.9 | 3.62 | 2.45 |
| 2022 | 3.02 | 5 | 1.94 |
| 2021 | 5.24 | 7.71 | 3.71 |
| 2020 | 6.06 | 7.87 | 4.43 |
| 2019 | 4.92 | 7.95 | 2.29 |
| 2018 | 3.1 | 4.15 | 2.29 |
| 2017 | 5.91 | 12.46 | 2.78 |
| 2016 | 7.19 | 11.44 | 5.23 |
| 2015 | 9.59 | 12.87 | 3.19 |
| 2014 | 2.61 | 4.05 | 1.7 |
| 2013 | 1.66 | 2.24 | 1.31 |
| 2012 | 1.76 | 2.39 | 1.26 |
| 2011 | 3.23 | 5.63 | 2.04 |
| 2010 | 4.78 | 6.4 | 3.24 |
| 2009 | 3.36 | 5.49 | 1.06 |
| 2008 | 1.84 | 3.57 | 0.81 |
| 2007 | 2.96 | 4.42 | 1.5 |
| 2006 | 1.83 | 2.53 | 1.37 |
| 2005 | 2.48 | 3.19 | 1.89 |
| 2004 | 3.8 | 5.33 | 2.75 |
| 2003 | 3.81 | 4.53 | 2.85 |
| 2002 | 4.57 | 5.08 | 3.72 |
| 2001 | 6.02 | 8.36 | 4.76 |
| 2000 | 10.15 | 14.07 | 8.27 |
| 1999 | 7.93 | 12.12 | 4.37 |
| 1998 | 7.54 | 9.26 | 6.24 |