| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.71 | 8.77 | 3.69 |
| 2024 | 3.11 | 5.95 | 2.39 |
| 2023 | 3.47 | 3.99 | 3.14 |
| 2022 | 3.57 | 5.74 | 2.86 |
| 2021 | 3.28 | 4.46 | 2.56 |
| 2020 | 3.01 | 3.58 | 2.54 |
| 2019 | 3.64 | 4.87 | 2.76 |
| 2018 | 3.76 | 5.43 | 2.52 |
| 2017 | 7.42 | 9.77 | 4.81 |
| 2016 | 9.93 | 13.52 | 7.49 |
| 2015 | 9.61 | 18.73 | 2.59 |
| 2014 | 3.57 | 5.91 | 2.53 |
| 2013 | 2.68 | 3.55 | 2.18 |
| 2012 | 3.25 | 4.57 | 2.35 |
| 2011 | 4.96 | 7.08 | 2.62 |
| 2010 | 4.51 | 5.5 | 3.77 |
| 2009 | 5.11 | 7.3 | 3.4 |
| 2008 | 7.97 | 22.02 | 2.18 |
| 2007 | 7.4 | 13.15 | 3.64 |
| 2006 | 2.91 | 3.7 | 2.05 |
| 2005 | 2.9 | 4.09 | 2.04 |
| 2004 | 4.98 | 8.91 | 3.33 |
| 2003 | 9.7 | 12.66 | 5.95 |
| 2002 | 8.18 | 10.09 | 5.53 |
| 2001 | 11.4 | 15.22 | 7.49 |
| 2000 | 10.82 | 13.51 | 5.09 |
| 1999 | 6.26 | 8.71 | 4.77 |
| 1998 | 5.66 | 7.3 | 4.52 |
| 1997 | 2.84 | 3.95 | 2.16 |