| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 2.37 | 2.89 | 1.95 |
| 2023 | 2.32 | 2.84 | 1.89 |
| 2022 | 2.82 | 3.72 | 2.21 |
| 2021 | 4.26 | 6.32 | 2.97 |
| 2020 | 2.82 | 5.23 | 2.03 |
| 2019 | 2.63 | 3.3 | 2.29 |
| 2018 | 3.22 | 4.62 | 2.19 |
| 2017 | 3.04 | 4.09 | 2.41 |
| 2016 | 2.37 | 2.8 | 1.87 |
| 2015 | 3.07 | 4.29 | 2.22 |
| 2014 | 3 | 4.46 | 2.29 |
| 2013 | 3.11 | 4.06 | 2.45 |
| 2012 | 3.27 | 4.08 | 2.7 |
| 2011 | 4.35 | 5.71 | 2.71 |
| 2010 | 4.18 | 5.3 | 3.06 |
| 2009 | 2.7 | 4.42 | 1.7 |
| 2008 | 2.66 | 5.49 | 1.47 |
| 2007 | 3.73 | 6.02 | 1.89 |
| 2006 | 1.08 | 1.92 | 0.86 |
| 2005 | 0.95 | 1.15 | 0.8 |
| 2004 | 1.31 | 1.67 | 0.83 |
| 2003 | 1.53 | 1.8 | 1.29 |
| 2002 | 2.11 | 2.75 | 1.51 |
| 2001 | 5.02 | 5.46 | 4.02 |
| 2000 | 4.46 | 5.28 | 3.36 |
| 1999 | 4.34 | 6.2 | 3.31 |
| 1998 | 6.03 | 9.05 | 4.45 |
| 1997 | 9.01 | 12.52 | 4.81 |