| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.83 | 2.98 | 2.74 |
| 2024 | 3.14 | 4.12 | 2.4 |
| 2023 | 4.38 | 5.79 | 3.79 |
| 2022 | 4.3 | 5.2 | 3.23 |
| 2021 | 3.26 | 4.43 | 2.62 |
| 2020 | 2.9 | 3.71 | 2.42 |
| 2019 | 2.76 | 3.2 | 2.56 |
| 2018 | 3.39 | 4.36 | 2.58 |
| 2017 | 3.56 | 3.89 | 3.37 |
| 2016 | 3.76 | 5.3 | 3.33 |
| 2015 | 3.99 | 6.02 | 3.01 |
| 2014 | 2.77 | 3.38 | 2.43 |
| 2013 | 3.5 | 4.04 | 2.78 |
| 2012 | 3.25 | 4.35 | 2.6 |
| 2011 | 4.67 | 6.1 | 3.9 |
| 2010 | 4.12 | 5.73 | 3.19 |
| 2009 | 2.99 | 3.7 | 2.34 |
| 2008 | 3.44 | 6.49 | 1.98 |
| 2007 | 5.54 | 8.02 | 3.32 |
| 2006 | 2.64 | 3.35 | 2.2 |
| 2005 | 2.95 | 3.59 | 1.82 |
| 2004 | 2.21 | 3.07 | 1.77 |