| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 7.15 | 7.86 | 6.35 |
| 2024 | 5.63 | 7.13 | 4.64 |
| 2023 | 5.93 | 7.23 | 4.55 |
| 2022 | 4.83 | 6.2 | 3.76 |
| 2021 | 5.35 | 7.07 | 4.05 |
| 2020 | 5.89 | 9.16 | 3.77 |
| 2019 | 12.65 | 30.14 | 4.88 |
| 2018 | 12.09 | 29.65 | 9.93 |
| 2017 | 13.62 | 15.98 | 12.25 |
| 2016 | 13.32 | 17.63 | 11.3 |
| 2015 | 21.37 | 24.72 | 16.82 |
| 2014 | 13.74 | 20.19 | 11.28 |
| 2013 | 13.37 | 15.25 | 11.63 |
| 2012 | 10.14 | 11.3 | 8.8 |
| 2011 | 10.48 | 14.59 | 7.62 |
| 2010 | 14.41 | 17.95 | 12.15 |
| 2009 | 10.38 | 16.7 | 5.88 |
| 2008 | 9.44 | 18.21 | 5.2 |
| 2007 | 18.6 | 23.41 | 14.35 |
| 2006 | 14.38 | 18.34 | 11.02 |
| 2005 | 5.54 | 12.45 | 2.54 |
| 2004 | 4.78 | 6.05 | 3.41 |
| 2003 | 4.34 | 5.2 | 3.24 |
| 2002 | 5.64 | 8.29 | 4.88 |
| 2001 | 9.91 | 14.65 | 3.82 |
| 2000 | 3.25 | 4.2 | 2.32 |
| 1999 | 3.06 | 5.53 | 1.06 |
| 1998 | 2.17 | 2.95 | 1.28 |
| 1997 | 4.52 | 6.35 | 2.38 |