** = Attrition rate is less than zero (0).
. = The necessary data are unavailable to calculate the attrition rate.
Calculation: Attrition is calculated by (1) dividing the high school enrollment in the end year by the high school enrollment in the base year; (2) multiplying the results from Calculation 1 by the ninth grade enrollment in the base year; (3) subtracting the results from Calculation 2 from 12th grade enrollment in the end year; and (4) dividing the results of Calculation 3 by the result of Calculation 2. The attrition rate results (percentages) were rounded to the nearest whole number.
Source: Intercultural Development Research Association, October 2010