| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.75 | 4.09 | 3.36 |
| 2024 | 3.26 | 4.41 | 2.7 |
| 2023 | 4.37 | 6.03 | 3.09 |
| 2022 | 7.81 | 13.32 | 4.77 |
| 2021 | 9.79 | 18.2 | 4.85 |
| 2020 | 4.06 | 5.47 | 3.21 |
| 2019 | 4.28 | 5.54 | 3.42 |
| 2018 | 4.7 | 6.31 | 3.51 |
| 2017 | 5.94 | 8.72 | 4.67 |
| 2016 | 5.73 | 6.65 | 4.87 |
| 2015 | 7.54 | 11.32 | 5.12 |
| 2014 | 6.66 | 8.06 | 5.78 |
| 2013 | 9.58 | 13.19 | 6.84 |
| 2012 | 12.96 | 16.45 | 8.15 |
| 2011 | 22.1 | 34.65 | 8.15 |
| 2010 | 19.65 | 37.7 | 10.81 |
| 2009 | 10.85 | 16.72 | 3.46 |
| 2008 | 8.07 | 15.2 | 2.64 |
| 2007 | 9.84 | 19.3 | 3.81 |
| 2006 | 2.5 | 4.12 | 1.65 |
| 2005 | 1.7 | 2.3 | 1.21 |
| 2004 | 2.7 | 3.9 | 2.03 |
| 2003 | 3.53 | 4.23 | 2.73 |
| 2002 | 5.06 | 5.59 | 4 |
| 2001 | 6.43 | 8.52 | 4.87 |
| 2000 | 6.45 | 8.75 | 4.95 |
| 1999 | 5.52 | 7.78 | 4.03 |
| 1998 | 4.67 | 5.89 | 4.03 |