The incidence of road traffic injuries varies considerably by geography.
The incidence of industrial bronchitis varies with age, job, exposure, and smoking.
The incidence of groping varies around the world, and some countries have acquired a reputation for it.
Within each disease type, the incidence of hypercalcemia varies greatly in reported series.
Yet, the incidence of sexual monogamy varies across cultures.
The incidence varies by geographic location, season of the year, and ethnicity.
In the 1960s, the incidence 5 years after a radical mastectomy varied from 0.07% to 0.45%.
The incidence of the disease varies greatly between ethnic groups, but is highest in Caucasian populations.
Their incidence varies within different societies at comparable stages of general development.
The incidence of taxation varies by system, and some systems may be viewed as progressive or regressive.