发案率的英文：
incidence

参考例句：

The incidence of cases of rape have increase over the last year.
强奸案的发案率在去年有所增加工厂。

The figures show evidence that murders in the nation's capital are beginning to level off.
这些数据证明该国首都的凶杀发案率正开始趋向稳定。

incidence是什么意思：
n. 影响（范围）；发生率；射入，入射角；关联

incidence relation
关联关系

axiom of incidence
关联公理

The incident was noticed in a magazine.
这一事件在一份杂志里述及。

They held an inquiry into the incident.
他们对这一事件展开调查。

The incident has hastened the disintegration of the club.
这一事件加速了该俱乐部的解体。