| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.84 | 2.63 | 1.23 |
| 2023 | 1.96 | 2.44 | 1.53 |
| 2022 | 1.43 | 1.8 | 1.1 |
| 2021 | 1.66 | 2.29 | 1.28 |
| 2020 | 1.69 | 2.4 | 1.34 |
| 2019 | 1.56 | 2.06 | 1.36 |
| 2018 | 1.56 | 1.82 | 1.32 |
| 2017 | 1.85 | 2.25 | 1.64 |
| 2016 | 1.62 | 1.94 | 1.38 |
| 2015 | 2.37 | 3.63 | 1.57 |
| 2014 | 1.9 | 2.58 | 1.65 |
| 2013 | 1.53 | 2.17 | 1.25 |
| 2012 | 1.61 | 2.04 | 1.29 |
| 2011 | 2.35 | 3.09 | 1.53 |
| 2010 | 2.41 | 3.42 | 1.81 |
| 2009 | 1.95 | 2.55 | 1.24 |
| 2008 | 3.08 | 7.41 | 1.01 |
| 2007 | 6.03 | 7.98 | 4.7 |
| 2006 | 3.54 | 5.41 | 1.77 |
| 2005 | 1.89 | 2.26 | 1.44 |
| 2004 | 2.6 | 3.47 | 1.9 |
| 2003 | 3.11 | 3.7 | 2.09 |
| 2002 | 2.82 | 3.09 | 2.38 |
| 2001 | 3.31 | 3.9 | 2.66 |
| 2000 | 3.12 | 3.86 | 2.58 |
| 1999 | 3.2 | 4.21 | 2.7 |
| 1998 | 4.02 | 5.83 | 2.17 |
| 1997 | 4.62 | 6.05 | 3.04 |