| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.94 | 2.44 | 1.76 |
| 2024 | 1.51 | 3.08 | 1.24 |
| 2023 | 1.57 | 1.82 | 1.36 |
| 2022 | 1.48 | 2.1 | 1.26 |
| 2021 | 1.47 | 1.66 | 1.34 |
| 2020 | 1.58 | 1.85 | 1.25 |
| 2019 | 1.65 | 2.16 | 1.36 |
| 2018 | 1.88 | 2.44 | 1.38 |
| 2017 | 3.03 | 4.02 | 2.34 |
| 2016 | 3.52 | 4.48 | 3.04 |
| 2015 | 4.76 | 7.97 | 3.18 |
| 2014 | 3.11 | 3.62 | 2.6 |
| 2013 | 2.37 | 3.37 | 2.01 |
| 2012 | 2.41 | 3.04 | 1.86 |
| 2011 | 3.34 | 4.03 | 2.45 |
| 2010 | 4.78 | 6.53 | 3.35 |
| 2009 | 4.06 | 5.53 | 2.34 |
| 2008 | 3.53 | 6.09 | 2.03 |
| 2007 | 4.83 | 7.2 | 2.89 |
| 2006 | 2.45 | 3.04 | 1.8 |
| 2005 | 1.98 | 2.62 | 0.84 |
| 2004 | 1.82 | 2.41 | 1.54 |
| 2003 | 2.13 | 2.69 | 1.55 |
| 2002 | 3.64 | 4.51 | 3.09 |
| 2001 | 4.86 | 6.05 | 3.89 |
| 2000 | 4.04 | 4.79 | 3.04 |
| 1999 | 2.94 | 3.65 | 2.41 |
| 1998 | 3.84 | 5.63 | 2.38 |
| 1997 | 4.58 | 7 | 2.73 |