| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.13 | 2.52 | 1.83 |
| 2024 | 1.31 | 3.6 | 0.81 |
| 2023 | 1.17 | 1.57 | 0.99 |
| 2022 | 1.18 | 1.5 | 0.98 |
| 2021 | 1.68 | 2.41 | 1.31 |
| 2020 | 1.58 | 1.81 | 1.38 |
| 2019 | 1.77 | 2.42 | 1.53 |
| 2018 | 2.27 | 2.73 | 1.73 |
| 2017 | 2.67 | 3.71 | 1.97 |
| 2016 | 2.97 | 3.87 | 2.55 |
| 2015 | 3.33 | 5.08 | 2.32 |
| 2014 | 2.21 | 2.6 | 1.76 |
| 2013 | 1.93 | 2.39 | 1.48 |
| 2012 | 2.39 | 3.02 | 1.61 |
| 2011 | 3.49 | 5.33 | 2.28 |
| 2010 | 3.33 | 3.97 | 2.47 |
| 2009 | 2.49 | 3.44 | 1.56 |
| 2008 | 2.42 | 3.98 | 1.26 |
| 2007 | 3.08 | 4.3 | 1.76 |
| 2006 | 2.37 | 3.1 | 1.77 |
| 2005 | 1.8 | 3.14 | 1.17 |
| 2004 | 2.14 | 3.01 | 1.46 |
| 2003 | 2.8 | 3.65 | 2.02 |
| 2002 | 5.42 | 5.83 | 4.89 |
| 2001 | 5.74 | 7.13 | 4.67 |
| 2000 | 4.22 | 5.54 | 3.04 |
| 1999 | 3.17 | 4.01 | 2.42 |
| 1998 | 2.93 | 3.65 | 2.15 |
| 1997 | 3.54 | 4.92 | 2.67 |