The NSCRC notes that, "Freshman enrollment by race/ethnicity is estimated data to account for differences in the data missing rate, because newer students have less opportunity for their race/ethnicity to have been reported. Adjustments were based on previous years’ patterns of data reporting. Missing data (for institutions that do not report to the Clearinghouse) and Unknown data (for students that do not report to the institution) account for an average of 25 percent of all enrollments, combined."