| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.37 | 2.73 | 2.13 |
| 2024 | 2.09 | 2.74 | 1.62 |
| 2023 | 2.86 | 3.33 | 2.45 |
| 2022 | 3.1 | 4.02 | 2.62 |
| 2021 | 3.49 | 4.6 | 2.99 |
| 2020 | 2.78 | 4.53 | 2.05 |
| 2019 | 2.18 | 3.7 | 1.04 |
| 2018 | 1.37 | 1.66 | 0.93 |
| 2017 | 1.98 | 2.78 | 1.51 |
| 2016 | 2.37 | 2.85 | 2 |
| 2015 | 2.76 | 4.56 | 1.73 |
| 2014 | 2 | 2.68 | 1.77 |
| 2013 | 2.46 | 3.1 | 1.92 |
| 2012 | 2.99 | 3.85 | 2.4 |
| 2011 | 5.15 | 9.23 | 3.32 |
| 2010 | 6.66 | 8.8 | 5.16 |
| 2009 | 4.98 | 6.02 | 4.04 |
| 2008 | 5.35 | 9.1 | 3.31 |
| 2007 | 3.67 | 5.73 | 2.13 |
| 2006 | 1.82 | 2.56 | 1.25 |
| 2005 | 1.65 | 2.25 | 1.24 |
| 2004 | 2.8 | 3.94 | 2.2 |
| 2003 | 3.59 | 4.38 | 2.26 |
| 2002 | 4.27 | 5.87 | 3.18 |
| 2001 | 6.07 | 7.25 | 4.51 |
| 2000 | 5.4 | 7.75 | 2.91 |
| 1999 | 3.56 | 4.28 | 2.88 |
| 1998 | 3.63 | 4.28 | 2.72 |