| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.83 | 9.38 | 3.69 |
| 2024 | 3.08 | 4.85 | 2.56 |
| 2023 | 3.05 | 3.53 | 2.64 |
| 2022 | 2.4 | 3.79 | 1.87 |
| 2021 | 1.91 | 2.24 | 1.65 |
| 2020 | 2.91 | 3.25 | 1.91 |
| 2019 | 3.29 | 3.53 | 3.11 |
| 2018 | 3.86 | 4.04 | 3.53 |
| 2017 | 4.21 | 4.4 | 4.04 |
| 2016 | 4.59 | 5.96 | 3.46 |
| 2015 | 5.28 | 8.65 | 3.06 |
| 2014 | 2.5 | 3.77 | 1.92 |
| 2013 | 2.28 | 2.76 | 1.89 |
| 2012 | 2.39 | 2.98 | 2.02 |
| 2011 | 3.4 | 4.32 | 2.13 |
| 2010 | 4.66 | 6.47 | 3.58 |
| 2009 | 4.45 | 7.28 | 2.26 |
| 2008 | 4.14 | 7.94 | 1.75 |
| 2007 | 7.08 | 10.37 | 4.61 |
| 2006 | 4.23 | 5.31 | 3.33 |
| 2005 | 3.89 | 5.07 | 2.47 |
| 2004 | 5.79 | 8.16 | 4.39 |
| 2003 | 6.88 | 9.5 | 4.49 |
| 2002 | 7.22 | 9.79 | 2.36 |
| 2001 | 4.88 | 6.21 | 3.21 |
| 2000 | 6.24 | 9.05 | 2.84 |
| 1999 | 3.45 | 4.45 | 2.42 |
| 1998 | 2.26 | 2.93 | 1.76 |
| 1997 | 3.25 | 4.88 | 2.28 |