| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.02 | 2.22 | 1.82 |
| 2024 | 2.32 | 3.05 | 1.81 |
| 2023 | 1.83 | 2.42 | 1.55 |
| 2022 | 1.99 | 2.61 | 1.52 |
| 2021 | 2.03 | 2.84 | 1.58 |
| 2020 | 2.65 | 3.83 | 1.95 |
| 2019 | 2.52 | 3.73 | 1.87 |
| 2018 | 3.44 | 4.44 | 2.54 |
| 2017 | 4.38 | 4.94 | 3.74 |
| 2016 | 4.5 | 6.3 | 3.76 |
| 2015 | 11.14 | 20.1 | 6.97 |
| 2014 | 5.65 | 13.26 | 4.01 |
| 2013 | 4.1 | 5.85 | 3.32 |
| 2012 | 4.21 | 5.21 | 3.53 |
| 2011 | 5.1 | 6.33 | 3.63 |
| 2010 | 7.92 | 11.02 | 5.64 |
| 2009 | 7 | 10.28 | 4.19 |
| 2008 | 7.02 | 12.57 | 3.87 |
| 2007 | 17.98 | 22.48 | 13.07 |