| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.03 | 2.51 | 1.82 |
| 2024 | 1.86 | 2.43 | 1.26 |
| 2023 | 2.09 | 2.81 | 1.55 |
| 2022 | 3.27 | 4.52 | 2.22 |
| 2021 | 2.48 | 4.51 | 1.27 |
| 2020 | 1.44 | 2.32 | 1.23 |
| 2019 | 1.62 | 2.05 | 1.26 |
| 2018 | 1.72 | 2.29 | 1.16 |
| 2017 | 2.52 | 3.15 | 2.13 |
| 2016 | 5.09 | 8.19 | 2.78 |
| 2015 | 8.49 | 22.88 | 3.63 |
| 2014 | 8.92 | 20.31 | 3.18 |
| 2013 | 2.98 | 4.04 | 2.31 |
| 2012 | 2.45 | 3.23 | 1.68 |
| 2011 | 3.22 | 4.29 | 2.07 |
| 2010 | 2.76 | 4 | 2.02 |
| 2009 | 1.81 | 2.77 | 0.83 |
| 2008 | 1.62 | 3.76 | 0.66 |
| 2007 | 2.51 | 4.17 | 0.82 |
| 2006 | 0.79 | 0.94 | 0.58 |
| 2005 | 0.95 | 1.37 | 0.69 |
| 2004 | 1.75 | 2.39 | 1.31 |
| 2003 | 1.69 | 1.97 | 1.47 |
| 2002 | 1.99 | 2.46 | 1.22 |
| 2001 | 2.48 | 3.01 | 1.74 |
| 2000 | 3.1 | 3.71 | 2.45 |
| 1999 | 2.79 | 3.63 | 2.2 |
| 1998 | 3.33 | 4.34 | 2.38 |
| 1997 | 4.31 | 6.05 | 2.8 |