| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 9.18 | 9.97 | 8.03 |
| 2024 | 9.67 | 16.11 | 6.99 |
| 2023 | 8.94 | 12.52 | 7.24 |
| 2022 | 7.64 | 9.98 | 6.25 |
| 2021 | 7.67 | 10.44 | 6.74 |
| 2020 | 9.22 | 12.4 | 7.47 |
| 2019 | 9.87 | 12.56 | 8.59 |
| 2018 | 11.48 | 16.19 | 8.64 |
| 2017 | 17.45 | 24.01 | 11.89 |
| 2016 | 20.45 | 28.76 | 16.62 |
| 2015 | 17.54 | 32.33 | 8.28 |
| 2014 | 7.88 | 8.84 | 6.05 |
| 2013 | 6.39 | 7.1 | 5.35 |
| 2012 | 6.58 | 8.72 | 5.11 |
| 2011 | 8.48 | 11.01 | 5.34 |
| 2010 | 10.72 | 13.8 | 7.71 |
| 2009 | 7.09 | 14.39 | 2.89 |
| 2008 | 5.58 | 10.05 | 2.22 |
| 2007 | 7.51 | 15.17 | 4.42 |
| 2006 | 4.15 | 4.96 | 3.29 |
| 2005 | 2.28 | 3.6 | 1.51 |
| 2004 | 3.63 | 5.73 | 1.99 |
| 2003 | 4.67 | 5.97 | 3.44 |
| 2002 | 8.83 | 10.53 | 7.13 |
| 2001 | 13.45 | 18.07 | 9.52 |
| 2000 | 11.35 | 19.12 | 5.63 |
| 1999 | 6.53 | 7.8 | 5.26 |
| 1998 | 5.9 | 9.15 | 3.55 |
| 1997 | 5.02 | 7.58 | 3.63 |