| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.94 | 3.07 | 2.73 |
| 2024 | 3.27 | 4.11 | 2.62 |
| 2023 | 3.93 | 5.14 | 3.02 |
| 2022 | 4.21 | 6.95 | 3.11 |
| 2021 | 3.05 | 4.18 | 2.43 |
| 2020 | 2.91 | 3.4 | 2.53 |
| 2019 | 3.53 | 5.85 | 2.78 |
| 2018 | 3.54 | 4.22 | 2.86 |
| 2017 | 5.3 | 7.66 | 3.55 |
| 2016 | 4.86 | 7.3 | 3.02 |
| 2015 | 2.79 | 4.44 | 1.61 |
| 2014 | 1.17 | 2.19 | 0.74 |
| 2013 | 0.85 | 0.99 | 0.76 |
| 2012 | 1.03 | 1.29 | 0.81 |
| 2011 | 1.39 | 1.74 | 0.99 |
| 2010 | 1.68 | 2.23 | 1.27 |
| 2009 | 1.84 | 2.3 | 1.13 |
| 2008 | 2.95 | 4 | 1.1 |
| 2007 | 2.57 | 3.04 | 2.13 |