| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.07 | 2.6 | 1.71 |
| 2024 | 2.16 | 2.37 | 1.78 |
| 2023 | 2.26 | 2.9 | 1.84 |
| 2022 | 1.92 | 2.68 | 1.22 |
| 2021 | 2.27 | 3.37 | 1.75 |
| 2020 | 2.67 | 4.78 | 1.75 |
| 2019 | 2.16 | 2.95 | 1.21 |
| 2018 | 2.16 | 3.72 | 1.13 |
| 2017 | 4 | 5.52 | 3.4 |
| 2016 | 3.95 | 6.3 | 3.18 |
| 2015 | 7.29 | 14.12 | 4.33 |
| 2014 | 4.05 | 7.95 | 2.46 |
| 2013 | 1.88 | 2.7 | 1.37 |
| 2012 | 2.26 | 2.95 | 1.62 |
| 2011 | 3.47 | 4.76 | 2.22 |
| 2010 | 3.42 | 4.42 | 2.55 |
| 2009 | 4.05 | 5.71 | 2.4 |
| 2008 | 6.58 | 20.21 | 1.87 |
| 2007 | 16.64 | 26.76 | 8.68 |
| 2006 | 4.98 | 8.87 | 2.46 |
| 2005 | 1.83 | 2.51 | 1.06 |
| 2004 | 3.05 | 4.53 | 2.32 |
| 2003 | 3.29 | 3.9 | 2.57 |
| 2002 | 3.95 | 4.98 | 2.36 |
| 2001 | 4.29 | 5.27 | 3.1 |
| 2000 | 1.62 | 2 | 1.25 |
| 1999 | 1.22 | 1.69 | 0.91 |
| 1998 | 1.13 | 1.36 | 0.94 |
| 1997 | 1.34 | 1.79 | 0.99 |