| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.59 | 3.18 | 2.14 |
| 2024 | 2.26 | 2.71 | 1.81 |
| 2023 | 2.5 | 2.84 | 2.14 |
| 2022 | 2.2 | 3.05 | 1.77 |
| 2021 | 2.56 | 3.21 | 2.1 |
| 2020 | 3.11 | 4.16 | 2.27 |
| 2019 | 1.95 | 2.71 | 1.48 |
| 2018 | 1.81 | 2.45 | 1.42 |
| 2017 | 2.28 | 2.73 | 1.88 |
| 2016 | 3.87 | 6.53 | 2.61 |
| 2015 | 7.08 | 11.76 | 5.04 |
| 2014 | 4.37 | 5.59 | 3.3 |
| 2013 | 3.46 | 4.71 | 2.61 |
| 2012 | 3.7 | 4.85 | 2.63 |
| 2011 | 6.59 | 10.08 | 4.37 |
| 2010 | 7.49 | 10.37 | 5.45 |
| 2009 | 6.81 | 7.68 | 5.91 |
| 2008 | 7.43 | 11.69 | 5.1 |