| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.1 | 5.05 | 3.55 |
| 2024 | 3.97 | 5.12 | 3.24 |
| 2023 | 3.41 | 3.9 | 2.92 |
| 2022 | 2.86 | 4.02 | 2.2 |
| 2021 | 2.57 | 3.09 | 2.24 |
| 2020 | 3.26 | 4.19 | 2.49 |
| 2019 | 2.87 | 3.96 | 2.15 |
| 2018 | 3.06 | 5.89 | 1.65 |
| 2017 | 3.98 | 5.04 | 3.32 |
| 2016 | 4.1 | 5.02 | 2.26 |
| 2015 | 4.67 | 7.71 | 2.67 |
| 2014 | 3.08 | 5.37 | 2.29 |
| 2013 | 5.49 | 14.02 | 2.42 |
| 2012 | 5.2 | 7.54 | 2.92 |
| 2011 | 5.54 | 7.69 | 3.21 |
| 2010 | 4.51 | 5.7 | 3.31 |
| 2009 | 4.08 | 6.25 | 1.96 |
| 2008 | 4.31 | 10.1 | 1.37 |
| 2007 | 7.16 | 10.19 | 2.29 |
| 2006 | 1.88 | 2.4 | 1.36 |
| 2005 | 1.75 | 2.56 | 1.2 |
| 2004 | 2.83 | 4.17 | 2.23 |
| 2003 | 3.35 | 4.4 | 2.28 |
| 2002 | 5.62 | 6.62 | 4.76 |
| 2001 | 5.23 | 7.31 | 3.57 |