| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.26 | 4.24 | 2.71 |
| 2024 | 2.24 | 3.22 | 1.51 |
| 2023 | 2.38 | 2.75 | 1.99 |
| 2022 | 2.53 | 2.99 | 1.99 |
| 2021 | 2.21 | 3.53 | 1.66 |
| 2020 | 1.88 | 2.28 | 1.56 |
| 2019 | 1.69 | 2.3 | 1.33 |
| 2018 | 1.87 | 2.89 | 1.08 |
| 2017 | 3.44 | 4.33 | 2.76 |
| 2016 | 4.31 | 5.5 | 3.53 |
| 2015 | 8.09 | 13.87 | 3.9 |
| 2014 | 3.72 | 5.71 | 2.88 |
| 2013 | 3.18 | 4.48 | 2.51 |
| 2012 | 4.08 | 5.56 | 2.18 |
| 2011 | 6.23 | 9.56 | 3.99 |
| 2010 | 6.31 | 8.66 | 4.16 |
| 2009 | 4.85 | 6.68 | 3.05 |
| 2008 | 3.94 | 6.23 | 2.03 |