| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.83 | 4.9 | 2.96 |
| 2024 | 2.37 | 6.08 | 1.15 |
| 2023 | 1.77 | 2.19 | 1.55 |
| 2022 | 2.15 | 3.14 | 1.66 |
| 2021 | 2.64 | 3.37 | 2.11 |
| 2020 | 2.76 | 3.75 | 2.32 |
| 2019 | 3.09 | 3.7 | 2.68 |
| 2018 | 3.39 | 4.26 | 2.65 |
| 2017 | 4.77 | 6.22 | 4.06 |
| 2016 | 5.61 | 9.65 | 4.51 |
| 2015 | 10.15 | 25.39 | 4.68 |
| 2014 | 5 | 6.24 | 4.27 |
| 2013 | 3.87 | 7.46 | 2.4 |
| 2012 | 2.48 | 3.33 | 1.94 |
| 2011 | 3.05 | 4.11 | 2.22 |
| 2010 | 3.91 | 5.25 | 2.95 |
| 2009 | 2.09 | 5.79 | 0.98 |
| 2008 | 1.68 | 3.85 | 0.79 |
| 2007 | 3.19 | 4.45 | 1.98 |
| 2006 | 1.47 | 2.25 | 1 |
| 2005 | 1.07 | 1.46 | 0.81 |
| 2004 | 1.81 | 2.4 | 1.32 |
| 2003 | 2.06 | 2.49 | 1.71 |
| 2002 | 2.52 | 3.2 | 1.88 |
| 2001 | 3.51 | 4.49 | 2.49 |
| 2000 | 4.89 | 6.4 | 4.17 |
| 1999 | 5.09 | 7.39 | 3.57 |
| 1998 | 8.1 | 10.22 | 6.51 |