| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.43 | 3.72 | 3.15 |
| 2024 | 3.06 | 4.01 | 2.49 |
| 2023 | 3.51 | 4.6 | 2.56 |
| 2022 | 2.8 | 3.9 | 2.33 |
| 2021 | 2.96 | 3.67 | 2.47 |
| 2020 | 2.69 | 3.14 | 2.29 |
| 2019 | 2.68 | 3.51 | 2.29 |
| 2018 | 2.51 | 3.23 | 2.05 |
| 2017 | 3.1 | 4.04 | 2.33 |
| 2016 | 3.82 | 5.45 | 2.88 |
| 2015 | 17.85 | 55.8 | 5.24 |
| 2014 | 14.36 | 21.25 | 11.93 |
| 2013 | 16.29 | 26.06 | 9.43 |
| 2012 | 12.93 | 17.03 | 5.46 |
| 2011 | 4.48 | 7.99 | 2.78 |
| 2010 | 2.27 | 2.78 | 1.69 |
| 2009 | 1.16 | 1.94 | 0.61 |
| 2008 | 1.14 | 1.88 | 0.49 |
| 2007 | 1.34 | 2.19 | 0.65 |
| 2006 | 0.81 | 1.25 | 0.57 |
| 2005 | 0.98 | 1.23 | 0.67 |
| 2004 | 1.22 | 1.77 | 0.79 |