| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.87 | 3.12 | 2.66 |
| 2024 | 2.96 | 3.37 | 2.53 |
| 2023 | 3.22 | 3.64 | 2.87 |
| 2022 | 3.35 | 4.55 | 2.55 |
| 2021 | 4.25 | 5.51 | 3.59 |
| 2020 | 4.88 | 6.65 | 3.35 |
| 2019 | 3.94 | 4.97 | 3.09 |
| 2018 | 3.79 | 4.76 | 3.06 |
| 2017 | 4.23 | 4.66 | 3.67 |
| 2016 | 6.91 | 10.19 | 4.24 |
| 2015 | 12.65 | 22.36 | 7.77 |
| 2014 | 9.22 | 11.17 | 7.58 |
| 2013 | 7.86 | 10.01 | 6.21 |
| 2012 | 7.04 | 8.23 | 5.53 |
| 2011 | 11.22 | 15.35 | 7.48 |
| 2010 | 14.92 | 20.49 | 11.15 |
| 2009 | 9.45 | 12.59 | 6.92 |