| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.02 | 1.33 | 0.86 |
| 2024 | 0.88 | 1 | 0.7 |
| 2023 | 1.01 | 1.2 | 0.86 |
| 2022 | 1.19 | 1.85 | 0.91 |
| 2021 | 1.17 | 1.48 | 0.91 |
| 2020 | 1.22 | 1.86 | 0.96 |
| 2019 | 0.93 | 1.15 | 0.69 |
| 2018 | 1.32 | 2.72 | 0.72 |
| 2017 | 2.23 | 2.6 | 1.87 |
| 2016 | 2.44 | 2.98 | 1.96 |
| 2015 | 2.18 | 3.9 | 1.24 |
| 2014 | 1.94 | 2.39 | 1.24 |
| 2013 | 1.32 | 1.69 | 1.05 |
| 2012 | 1.45 | 1.81 | 1.19 |
| 2011 | 2.53 | 3.51 | 1.45 |
| 2010 | 3.87 | 7.75 | 2.26 |
| 2009 | 3.82 | 5.81 | 1.71 |
| 2008 | 4.53 | 9.17 | 1.26 |
| 2007 | 7.26 | 11.37 | 3.88 |
| 2006 | 6.08 | 8.43 | 3.17 |