| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 8.72 | 12.35 | 7 |
| 2024 | 6.11 | 8.77 | 4.48 |
| 2023 | 6.77 | 9.54 | 6 |
| 2022 | 6.59 | 8.08 | 4.48 |
| 2021 | 4.11 | 10.9 | 2.98 |
| 2020 | 4.19 | 6.67 | 2.91 |
| 2019 | 6.28 | 8.2 | 4.83 |
| 2018 | 8.8 | 12.27 | 6.65 |
| 2017 | 14.82 | 20.93 | 10.26 |
| 2016 | 8.56 | 10.61 | 6.33 |
| 2015 | 11.44 | 20.95 | 7.11 |
| 2014 | 6.79 | 9.93 | 4.92 |
| 2013 | 5.53 | 6.41 | 5.07 |
| 2012 | 20.78 | 26.99 | 8.3 |
| 2011 | 23.12 | 29.39 | 17.31 |
| 2010 | 21.58 | 27.91 | 15.96 |
| 2009 | 13.36 | 19.19 | 7.99 |
| 2008 | 14.03 | 22.96 | 6.76 |
| 2007 | 15.31 | 23.58 | 6.41 |
| 2006 | 5.86 | 8.04 | 3.48 |
| 2005 | 2.97 | 3.7 | 2.01 |
| 2004 | 3.8 | 5.2 | 3.11 |
| 2003 | 1.16 | 1.16 | 1.16 |
| 2002 | 1.75 | 2.19 | 0.91 |
| 2001 | 1.6 | 1.91 | 1.21 |
| 2000 | 1.49 | 1.85 | 1.24 |
| 1999 | 1.53 | 2.04 | 1.23 |
| 1998 | 2.25 | 2.86 | 1.58 |
| 1997 | 4.69 | 8.85 | 2.79 |