Measuring productivity

I have a time series set of data of employees in the motor vehicle industry from 1972-2001 (in thousands) as well as average weekly hours of employees in the motor vehicle industry and also motor vehicle output (in billions of dollars). I need to measure productivity, as either output/unit of labor or else output/hour, but I need to know how I should exactly calculate this, if it is measured in dollars or? and how to calculate it for the best measure of productivity?