Rate

An expression of the frequency with which an event occurs in a defined population, usually in a specified period of time. The components of a rate are the numerator, the denominator, the specified time in which events occur, and usually a multiplier, that converts the rate from a fraction or decimal to a whole number. The numerator is the absolute number of occurrences of the event being studied in a specified time. The denominator is the reference population (or population being studied) at the same time (17,23).