| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 18.4 | 39.5 | 10.72 |
| 2024 | 11.34 | 20.18 | 7.56 |
| 2023 | 13.89 | 18.31 | 11.3 |
| 2022 | 8.04 | 12.67 | 4.93 |
| 2021 | 4.6 | 8.1 | 2.74 |
| 2020 | 4.66 | 5.83 | 3.53 |
| 2019 | 5.6 | 8.17 | 4.17 |
| 2018 | 6.08 | 8.13 | 5.19 |
| 2017 | 8.97 | 12.55 | 7.7 |
| 2016 | 11.33 | 17.3 | 9.71 |
| 2015 | 13.3 | 19.98 | 8.02 |
| 2014 | 7.77 | 11.86 | 5.09 |
| 2013 | 5.13 | 7.02 | 3.69 |
| 2012 | 5.83 | 8.13 | 4.48 |
| 2011 | 10.1 | 14.14 | 4.88 |
| 2010 | 8.72 | 14.14 | 5.65 |
| 2009 | 4.93 | 7.54 | 3.26 |
| 2008 | 5.49 | 9.62 | 2.36 |
| 2007 | 6.42 | 8.48 | 4.23 |
| 2006 | 3.75 | 6.14 | 1.86 |
| 2005 | 2.65 | 3.26 | 1.71 |
| 2004 | 3.72 | 5.05 | 2.59 |
| 2003 | 5.49 | 7.69 | 3.41 |
| 2002 | 6.99 | 8.3 | 5.09 |
| 2001 | 8 | 10.46 | 5.11 |
| 2000 | 8.33 | 11.64 | 5.77 |
| 1999 | 7.27 | 10.9 | 5.15 |
| 1998 | 8.78 | 14.84 | 3.99 |