| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 7.7 | 9.19 | 6.84 |
| 2024 | 9.78 | 20.85 | 4.5 |
| 2023 | 16.15 | 21.76 | 13.26 |
| 2022 | 12.7 | 23.46 | 7.87 |
| 2021 | 7.51 | 18.45 | 5.7 |
| 2020 | 10.61 | 15.45 | 6.91 |
| 2019 | 13.98 | 21.16 | 9.47 |
| 2018 | 20.19 | 31.48 | 9 |
| 2017 | 20.99 | 33.51 | 16.25 |
| 2016 | 26.71 | 40.68 | 13.85 |
| 2015 | 28.27 | 54.33 | 13.99 |
| 2014 | 15.59 | 23.83 | 11.81 |
| 2013 | 12.23 | 17.99 | 6.38 |
| 2012 | 4.97 | 6.93 | 3.93 |
| 2011 | 6.57 | 8.89 | 4.43 |
| 2010 | 6.4 | 8.3 | 4.66 |
| 2009 | 4.4 | 6.85 | 2.55 |
| 2008 | 4.39 | 8.39 | 2.12 |
| 2007 | 6.99 | 11.12 | 4.31 |
| 2006 | 4.2 | 5.37 | 3.49 |
| 2005 | 5.5 | 8.04 | 3.9 |
| 2004 | 8.56 | 11.68 | 6.01 |
| 2003 | 8.02 | 14.83 | 4.42 |
| 2002 | 11.25 | 12.62 | 8.03 |
| 2001 | 17.23 | 24.47 | 12.11 |
| 2000 | 27.33 | 42.85 | 10.66 |
| 1999 | 10.3 | 13.82 | 6.11 |
| 1998 | 6.22 | 9.91 | 4.35 |
| 1997 | 4.71 | 7.95 | 3.04 |