| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.96 | 2.32 | 1.6 |
| 2023 | 1.6 | 1.75 | 1.43 |
| 2022 | 1.51 | 1.68 | 1.38 |
| 2021 | 1.46 | 1.87 | 1.21 |
| 2020 | 1.38 | 1.55 | 1.24 |
| 2019 | 1.5 | 1.73 | 1.27 |
| 2018 | 1.53 | 1.7 | 1.31 |
| 2017 | 1.74 | 1.91 | 1.62 |
| 2016 | 1.69 | 2.1 | 1.54 |
| 2015 | 3.31 | 4.28 | 2.21 |
| 2014 | 1.97 | 3.5 | 1.49 |
| 2013 | 1.75 | 2.08 | 1.48 |
| 2012 | 1.41 | 1.71 | 1.21 |
| 2011 | 1.53 | 1.84 | 1.28 |
| 2010 | 2.58 | 4.9 | 1.61 |
| 2009 | 2.8 | 5.11 | 2.32 |
| 2008 | 2.44 | 4.53 | 1.63 |
| 2007 | 4.49 | 7.64 | 1.99 |
| 2006 | 2.39 | 3.42 | 1.51 |
| 2005 | 2.66 | 3.29 | 1.7 |
| 2004 | 4.78 | 14.54 | 2.13 |
| 2003 | 8.85 | 12.5 | 3.47 |
| 2002 | 3.39 | 4.5 | 2.07 |
| 2001 | 3.01 | 3.78 | 2.03 |
| 2000 | 2.9 | 3.63 | 2.29 |
| 1999 | 3.23 | 4.72 | 2.43 |
| 1998 | 10.05 | 12.93 | 7.2 |
| 1997 | 15.28 | 24.74 | 8.83 |