| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.07 | 5.43 | 4.61 |
| 2024 | 4.6 | 6.08 | 3.69 |
| 2023 | 5.02 | 6.2 | 4.06 |
| 2022 | 4.26 | 5.36 | 3.28 |
| 2021 | 5.88 | 7.73 | 4.82 |
| 2020 | 6.95 | 9.41 | 4.56 |
| 2019 | 4.8 | 5.82 | 3.95 |
| 2018 | 4.53 | 6.04 | 3.35 |
| 2017 | 6.98 | 8.44 | 5.9 |
| 2016 | 8.42 | 10.94 | 7.62 |
| 2015 | 12.11 | 21.14 | 7.53 |
| 2014 | 5.83 | 9.01 | 4.61 |
| 2013 | 6.1 | 7.47 | 4.39 |
| 2012 | 5.44 | 7.2 | 3.62 |
| 2011 | 8.44 | 10.56 | 7.07 |
| 2010 | 8.48 | 12.53 | 5.44 |
| 2009 | 4.66 | 5.54 | 3.91 |
| 2008 | 6.34 | 34.75 | 2.53 |
| 2007 | 20.59 | 30.95 | 12.38 |
| 2006 | 9.82 | 15.13 | 4.76 |
| 2005 | 4.24 | 5.58 | 2.85 |
| 2004 | 6.87 | 12.21 | 4.68 |
| 2003 | 10.71 | 13.43 | 8.09 |
| 2002 | 13.2 | 14.79 | 11.62 |
| 2001 | 14.19 | 17.15 | 11 |
| 2000 | 13.99 | 21.55 | 4.79 |
| 1999 | 4.42 | 5.57 | 3.42 |
| 1998 | 4.63 | 5.8 | 3.49 |