| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 9.18 | 9.47 | 8.82 |
| 2024 | 8.38 | 9.33 | 7.84 |
| 2023 | 8.31 | 10.2 | 5.8 |
| 2022 | 5.84 | 6.39 | 4.87 |
| 2021 | 9.24 | 16.52 | 4.92 |
| 2020 | 10.75 | 16.05 | 5.76 |
| 2019 | 7.34 | 8.96 | 6.49 |
| 2018 | 7.49 | 8.16 | 6.89 |
| 2017 | 9.81 | 11.91 | 7.66 |
| 2016 | 10.74 | 17.15 | 7.82 |
| 2015 | 10.85 | 14.36 | 8.67 |
| 2014 | 21.53 | 53.43 | 8.91 |
| 2013 | 26.41 | 54.31 | 13 |
| 2012 | 10.76 | 13 | 7.94 |
| 2011 | 9.75 | 12.3 | 7.66 |
| 2010 | 11.78 | 12.89 | 10.36 |
| 2009 | 10 | 13.27 | 7.2 |
| 2008 | 10.26 | 18.91 | 5.97 |
| 2007 | 18.66 | 28.87 | 14.24 |
| 2006 | 12.83 | 14.98 | 11.51 |
| 2005 | 5.94 | 12.86 | 3.11 |
| 2004 | 5.73 | 7.88 | 4.07 |
| 2003 | 5.89 | 6.6 | 5.21 |
| 2002 | 6.48 | 7.24 | 5.49 |
| 2001 | 10.41 | 15.19 | 4.94 |
| 2000 | 2.13 | 2.7 | 1.64 |
| 1999 | 2.47 | 4.33 | 1.92 |
| 1998 | 2.86 | 4.07 | 1.67 |
| 1997 | 6.4 | 9.33 | 3.3 |