Coefficient of Variation (CV)
The coefficient of variation is reported as a percentage and calculated from the average and standard deviation as follows:
100 * Standard Deviation
For example, a CV of 3% means the standard deviation is equal to 3% of the average. For some measures, the standard deviation increases as the average increases. In this case, the CV is the best way to summarize the variation. In other cases the standard deviation does not change with the average. In this case, the standard deviation is the best way to summarize the variation.