Categorical Statistics
The categorical U.S. Drought Monitor statistic is the percent of the area in a certain drought category, and excludes areas that are better or worse. For example, the D0 category is labeled as such and only shows the percent of the area experiencing abnormally dry conditions.

Someone using categorical statistics might say that as of May 26, 2015, 9.32 percent of Utah was in extreme (D3) drought, 25.07 percent was in severe (D2) drought, 56.24 percent was in moderate (D1) drought, and 9.37 percent of the state was abnormally dry (D0).
Note that these statistics will add up to 100 percent for a given week.