| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.86 | 3.8 | 2.02 |
| 2024 | 1.73 | 2.48 | 1.38 |
| 2023 | 2.71 | 4.37 | 1.75 |
| 2022 | 4.13 | 6.35 | 3.03 |
| 2021 | 13.27 | 22.69 | 5.23 |
| 2020 | 9.67 | 15.8 | 4.77 |
| 2019 | 3.8 | 5.18 | 2.54 |
| 2018 | 2.84 | 3.4 | 2.56 |
| 2017 | 3.41 | 3.92 | 3.03 |
| 2016 | 3.62 | 4.81 | 2.38 |
| 2015 | 3.47 | 4.08 | 2.22 |
| 2014 | 2.16 | 2.55 | 1.87 |
| 2013 | 2.89 | 4.28 | 2.23 |
| 2012 | 16.82 | 38.05 | 2.82 |
| 2011 | 16.21 | 36.46 | 4.53 |
| 2010 | 3.85 | 4.59 | 2.81 |
| 2009 | 3.37 | 5.05 | 1.4 |
| 2008 | 2.4 | 4.66 | 1.03 |
| 2007 | 2.89 | 4.31 | 1.32 |
| 2006 | 1.15 | 1.45 | 0.84 |
| 2005 | 1.08 | 1.44 | 0.8 |
| 2004 | 1.68 | 2.13 | 1.3 |
| 2003 | 2.03 | 2.51 | 1.52 |
| 2002 | 2.84 | 3.29 | 1.98 |
| 2001 | 3.51 | 4.2 | 2.58 |
| 2000 | 3.65 | 4.62 | 2.68 |
| 1999 | 3.49 | 4.65 | 2.88 |
| 1998 | 3.29 | 3.93 | 2.84 |
| 1997 | 4.53 | 6.22 | 3.28 |