| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 4.04 | 5 | 3.08 |
| 2023 | 5.71 | 7.87 | 4.2 |
| 2022 | 6.58 | 9.34 | 4.83 |
| 2021 | 11.68 | 16.65 | 8.24 |
| 2020 | 9.53 | 14.11 | 5.71 |
| 2019 | 6.14 | 8.16 | 3.19 |
| 2018 | 4.77 | 6.88 | 3.09 |
| 2017 | 4.1 | 6.16 | 2.9 |
| 2016 | 2.64 | 3.13 | 2.04 |
| 2015 | 2.38 | 3 | 2 |
| 2014 | 1.8 | 2.16 | 1.56 |
| 2013 | 2.42 | 3.77 | 1.59 |
| 2012 | 4.99 | 6.51 | 3.18 |
| 2011 | 6.82 | 7.71 | 5.58 |
| 2010 | 7.47 | 9.06 | 5.65 |
| 2009 | 6.2 | 9.06 | 4.67 |
| 2008 | 8.65 | 18.81 | 4.09 |
| 2007 | 12.84 | 20.91 | 7.66 |
| 2006 | 4.2 | 7.64 | 2.49 |
| 2005 | 2.86 | 3.2 | 2.41 |
| 2004 | 2.89 | 3.49 | 2.55 |
| 2003 | 2.44 | 2.75 | 2.17 |
| 2002 | 3.22 | 4.09 | 2.4 |
| 2001 | 4.49 | 6.12 | 2.58 |
| 2000 | 5.99 | 7.18 | 5.06 |
| 1999 | 6.95 | 9.48 | 4.87 |