| 2016 | 2017 | 2018 | 2019 | 2020 |
最大值 | 0.8466 | 0.8483 | 0.8493 | 0.8525 | 0.8580 |
最小值 | 0.5829 | 0.5899 | 0.5972 | 0.6061 | 0.6241 |
均值 | 0.7003 | 0.7061 | 0.7113 | 0.7177 | 0.7302 |
标准差 | 0.0775 | 0.0758 | 0.0738 | 0.0715 | 0.0663 |