percentage point
noun
Definitions
One hundredth of a given value, used to measure the difference of two percentages.
Example: The difference between 20 percent and 30 percent is 10 percentage points, not 10 percent. In fact, an increase from 20 to 30 percent is an increase of 50 percent. Only if, for example, 20 percent of buyers choose a certain company's products in one year and 22 percent do so the next year, can one speak of an increase of 10 percent.