| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.7 | 2.78 | 2.63 |
| 2024 | 3.22 | 4.55 | 1.91 |
| 2023 | 7.59 | 12.07 | 4.19 |
| 2022 | 10.68 | 16.85 | 6.76 |
| 2021 | 13.04 | 22.07 | 5.85 |
| 2020 | 4.08 | 9.34 | 2.57 |
| 2019 | 3.64 | 4.53 | 2.99 |
| 2018 | 4.45 | 7 | 2.62 |
| 2017 | 4.51 | 6.94 | 3.28 |
| 2016 | 3.12 | 4 | 2.24 |
| 2015 | 3.09 | 4.72 | 1.77 |
| 2014 | 1.93 | 2.82 | 1.51 |
| 2013 | 2.71 | 4.64 | 1.94 |
| 2012 | 4.57 | 6.17 | 2.66 |
| 2011 | 3.64 | 4.32 | 2.8 |
| 2010 | 2.93 | 4.78 | 1.88 |
| 2009 | 2.37 | 3.67 | 1.13 |
| 2008 | 1.77 | 3.45 | 0.88 |
| 2007 | 2.41 | 3.93 | 1.16 |
| 2006 | 0.91 | 1.26 | 0.76 |
| 2005 | 0.76 | 0.92 | 0.64 |
| 2004 | 1.08 | 1.52 | 0.8 |
| 2003 | 1.26 | 1.49 | 1.11 |
| 2002 | 1.63 | 1.94 | 1.24 |
| 2001 | 2.41 | 3.31 | 1.64 |
| 2000 | 3.05 | 4.39 | 2.37 |
| 1999 | 2.81 | 3.61 | 2.16 |
| 1998 | 7.09 | 9.92 | 4.59 |
| 1997 | 8.88 | 11 | 6.91 |