| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.82 | 4.79 | 3.05 |
| 2024 | 3.15 | 4.41 | 2.45 |
| 2023 | 3.01 | 3.63 | 2.7 |
| 2022 | 3.3 | 3.98 | 2.77 |
| 2021 | 4.3 | 5.9 | 3.51 |
| 2020 | 4.83 | 5.67 | 4.03 |
| 2019 | 4.83 | 6.38 | 3.91 |
| 2018 | 4.93 | 8.12 | 3.36 |
| 2017 | 7.04 | 9.46 | 4.91 |
| 2016 | 8.86 | 12.39 | 6.98 |
| 2015 | 10.05 | 18.47 | 5.85 |
| 2014 | 7.55 | 9.83 | 6.09 |
| 2013 | 6.06 | 8.94 | 4.25 |
| 2012 | 4.48 | 5.2 | 3.58 |
| 2011 | 5.41 | 6.55 | 3.74 |
| 2010 | 5.46 | 7.84 | 3.87 |
| 2009 | 6.8 | 9.76 | 3.82 |
| 2008 | 7.66 | 19.69 | 2.12 |
| 2007 | 6.65 | 11.53 | 2.15 |
| 2006 | 2.47 | 2.8 | 1.99 |
| 2005 | 2.7 | 4.19 | 1.74 |
| 2004 | 4.51 | 6.38 | 2.87 |
| 2003 | 5.53 | 6.36 | 4.43 |
| 2002 | 6.46 | 7.68 | 4.46 |
| 2001 | 7.79 | 10.24 | 4.98 |
| 2000 | 5.8 | 8.91 | 2.14 |
| 1999 | 2.07 | 2.98 | 1.4 |
| 1998 | 1.51 | 1.97 | 1.26 |
| 1997 | 1.52 | 2.15 | 1.21 |