| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.01 | 5.45 | 4.16 |
| 2024 | 5.68 | 10.56 | 4.01 |
| 2023 | 3.71 | 11.01 | 1.85 |
| 2022 | 1.92 | 2.65 | 1.34 |
| 2021 | 1.41 | 1.91 | 1.14 |
| 2020 | 1.73 | 2.41 | 1.46 |
| 2019 | 1.82 | 2.45 | 1.47 |
| 2018 | 1.95 | 2.66 | 1.44 |
| 2017 | 3.09 | 4.14 | 2.38 |
| 2016 | 4.51 | 8.15 | 3.67 |
| 2015 | 4.85 | 7.91 | 2.16 |
| 2014 | 2.7 | 3.4 | 2.2 |
| 2013 | 1.78 | 2.57 | 1.38 |
| 2012 | 1.55 | 1.85 | 1.27 |
| 2011 | 2.18 | 2.76 | 1.42 |
| 2010 | 2.69 | 3.49 | 1.94 |
| 2009 | 2.96 | 3.86 | 2.14 |
| 2008 | 3.04 | 5.58 | 1.14 |
| 2007 | 2.21 | 3.52 | 1.02 |
| 2006 | 0.98 | 1.17 | 0.68 |
| 2005 | 0.83 | 1.08 | 0.62 |
| 2004 | 1.31 | 1.85 | 0.96 |
| 2003 | 1.54 | 1.8 | 1.27 |
| 2002 | 2.4 | 2.67 | 1.95 |
| 2001 | 4.07 | 4.87 | 3.06 |
| 2000 | 4.42 | 5.74 | 2.71 |
| 1999 | 2.6 | 3.54 | 1.77 |
| 1998 | 6.33 | 8.92 | 3.26 |
| 1997 | 3.67 | 5.68 | 2.83 |