excess mortality       
noun [ U ] uk/ˌek.ses mɔːˈtæl.ə.ti/ us/ekˌses mɔːrˈtæl.ə.t̬i/
 超额死亡率
the number of deaths during a particular period above the usual, expected number under normal conditions, which can show the effect of something like a disease or harmful event
  We should develop methods to rapidly assess total excess mortality after natural disasters. 我们应该制定方法,迅速评估自然灾害后的总超额死亡率。 
 They analysed excess mortality from the Coronavirus (Covid-19) pandemic. 他们分析了冠状病毒(Covid-19)大流行期间的超额死亡率。 
 Synonym: excess deaths
 - More examples
 - Their paper reviews the excess mortality of the 1918 influenza pandemic.
 - In the absence of a reliable figure from the government, researchers attempted in the months since the storm to calculate the "excess mortality".
 - Excess mortality would be a precise indicator of the severity of the famine.
 - In the year after breaking a hip, the excess mortality was between 20 and 33 percent.