| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 3.9 | 4.84 | 3.25 |
| 2023 | 3.27 | 3.62 | 2.83 |
| 2022 | 3.81 | 5.06 | 3.02 |
| 2021 | 5.58 | 7.62 | 4.37 |
| 2020 | 3.2 | 5.74 | 2.15 |
| 2019 | 2.81 | 3.38 | 2.54 |
| 2018 | 3.25 | 4.16 | 2.52 |
| 2017 | 3.31 | 4.06 | 2.68 |
| 2016 | 2.38 | 2.9 | 2.01 |
| 2015 | 2.78 | 4.75 | 1.79 |
| 2014 | 2.4 | 3.19 | 1.93 |
| 2013 | 2.34 | 2.71 | 1.91 |
| 2012 | 2.53 | 3.1 | 2.11 |
| 2011 | 3.68 | 4.7 | 2.57 |
| 2010 | 5.02 | 7.61 | 3.74 |
| 2009 | 5.29 | 7.84 | 2.34 |
| 2008 | 5.63 | 11.98 | 2.04 |
| 2007 | 8.95 | 12.68 | 5.07 |
| 2006 | 3.24 | 5.55 | 2.47 |
| 2005 | 3.44 | 4.94 | 2.14 |
| 2004 | 6.05 | 12.53 | 2.52 |
| 2003 | 7.26 | 9.76 | 3.95 |
| 2002 | 8.4 | 11.92 | 6.39 |
| 2001 | 12.07 | 13.04 | 11.53 |
| 2000 | 10 | 13.12 | 5.69 |
| 1999 | 6.6 | 10 | 5.11 |
| 1998 | 6.57 | 7.88 | 5.25 |
| 1997 | 7.94 | 13.48 | 5.2 |