Which mortality rate divides by the estimated total mid-year population?

1. A cause-specific mortality rate narrows only the numerator, to deaths from one cause. 2. Its denominator stays the whole population at the midpoint of the period. 3. An age-specific rate narrows the denominator to that age group, and a sex-specific rate narrows it to one sex. 4. The maternal mortality rate uses live births in the denominator instead of a population count. _Source: CDC Principles of Epidemiology in Public Health Practice (3rd ed., US federal, public domain), Lesson 3 "Measures of Risk", section Cause-specific mortality rate_