| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.77 | 1.96 | 1.68 |
| 2024 | 1.65 | 2.16 | 1.31 |
| 2023 | 1.85 | 2.1 | 1.61 |
| 2022 | 1.79 | 2.2 | 1.51 |
| 2021 | 1.88 | 2.38 | 1.67 |
| 2020 | 2.28 | 3.32 | 1.52 |
| 2019 | 1.9 | 2.34 | 1.61 |
| 2018 | 2.08 | 2.84 | 1.44 |
| 2017 | 3.33 | 4.35 | 2.61 |
| 2016 | 4.47 | 5.56 | 4.17 |
| 2015 | 5.86 | 9.73 | 4 |
| 2014 | 3.53 | 4.91 | 2.63 |
| 2013 | 2.68 | 3.39 | 1.89 |
| 2012 | 2.53 | 3.04 | 1.83 |
| 2011 | 3.89 | 4.79 | 2.64 |
| 2010 | 4.41 | 5.93 | 3.49 |
| 2009 | 2.82 | 3.63 | 2.03 |
| 2008 | 4.77 | 9.26 | 1.74 |
| 2007 | 6.03 | 8.7 | 3.4 |
| 2006 | 2.39 | 3.62 | 1.13 |
| 2005 | 1.06 | 1.23 | 0.83 |
| 2004 | 1.71 | 2.75 | 1.01 |
| 2003 | 2.89 | 3.35 | 1.96 |
| 2002 | 3.63 | 4.35 | 2.78 |
| 2001 | 3.72 | 4.68 | 2.75 |
| 2000 | 7.18 | 8.34 | 5.2 |
| 1999 | 4.99 | 6.78 | 3.92 |
| 1998 | 9 | 11.72 | 6.32 |