This article describes a ratio measure. In the standard operationalization, the numerator of the measure is number of abortions (view other ratio measures with this numerator) and the denominator of the measure is number of females of childbearing age (view other ratio measures with this denominator). The denominator used for reporting is 1000. The measurement period is a year.
The numerator counts the number of occurrences of an event during the measurement period.
The denominator counts the total count of some type of entity, and an appropriate convention is set regarding the time within the measurement period that this count is calculated.