| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.59 | 4.41 | 3.12 |
| 2024 | 3.08 | 4.11 | 2.37 |
| 2023 | 4.01 | 4.99 | 3.37 |
| 2022 | 3.85 | 5.37 | 2.86 |
| 2021 | 4.34 | 5.94 | 3.45 |
| 2020 | 4.24 | 5.16 | 3.71 |
| 2019 | 3.92 | 5.47 | 2.95 |
| 2018 | 3.59 | 4.64 | 2.9 |
| 2017 | 4.88 | 6.12 | 4.07 |
| 2016 | 6.9 | 9.86 | 5.7 |
| 2015 | 12.02 | 22.22 | 6.95 |
| 2014 | 6.87 | 11.65 | 4.73 |
| 2013 | 6.14 | 7.87 | 5.15 |
| 2012 | 17.62 | 33.98 | 5.11 |
| 2011 | 13.8 | 17.94 | 10.18 |
| 2010 | 14.3 | 21.34 | 10.2 |
| 2009 | 5.97 | 10.92 | 2.86 |
| 2008 | 4.91 | 10.32 | 2.12 |
| 2007 | 6.36 | 9.66 | 2.8 |
| 2006 | 3.04 | 3.78 | 2.42 |
| 2005 | 3.66 | 5.02 | 2.69 |
| 2004 | 5.4 | 7.59 | 3.93 |
| 2003 | 7.12 | 8.42 | 5.38 |
| 2002 | 9.51 | 11.09 | 7.84 |
| 2001 | 13.02 | 14.56 | 10.65 |
| 2000 | 18.9 | 23.38 | 8.12 |
| 1999 | 7.62 | 10.4 | 5.25 |
| 1998 | 6.81 | 10 | 4.68 |
| 1997 | 4.69 | 6.15 | 3.91 |