This 'natality depression' reached its maximum levels about 6 months after the pandemic peak of the previous autumn.

这“抑郁症”去年秋季疫情高峰后大约6个月达到了最高水平。

He worked for NATO and studied natality.

他为北大西洋公约组织服务，研究出率。

The dip in birth rates in spring of 1919 was followed by 'a compensatory natality increase in late autumn 1919 and early spring 1920, when natality significantly exceeded the expected rates.'

1919年春季出率下降之后，“1919年深秋和1920年初春的出率出现了补偿性上升，当时的出率明显超过了预期。”