Although college-bound high school seniors from the class of 2009 rank as the most racially and ethnically diverse group ever to take the SAT, average scores fell slightly from 2008, according to the College Board. In a report released by the College Board on Tuesday, data revealed that of the 1,530,000 college-bound seniors taking the exam roughly 40 percent were minorities, an increase of nearly 11 percent from a decade ago. Blacks and Hispanics accounted for 12.2 percent and 13.5 percent of the minorities taking the test this year, respectively.

Hispanic students, which include those of Mexican American, Puerto Rican, Latin Caribbean and Latin American descent,  comprise the largest and fastest growing minority student bloc taking the SAT.  In 1999, Hispanics accounted for 7.8 percent of students taking the exam.

The 2009 national average SAT math score of 515 remained unchanged from last year. However, the nation’s average math scores have increased four points overall in the last decade. In contrast, national averages for critical reading (501) and writing (493) each fell a point from their 2008 scores.

This year, average critical-reading scores also fell slightly from the past year for under-represented college-bound minorities. Averages for Blacks (429) and Mexican Americans (453) each dropped a point. Puerto Rican students’ average fell four points to 452. Whites’ average remained unchanged at 528.

Writing scores for under-represented college-bound minorities remained flat or fell slightly from 2008. Blacks had an average score of 421 for the second straight year. Mexican American students’ average dropped a point to 446. Puerto Rican students’ average increased two points to 445. The White-student average rose a point to 518.

Laurence Bunin, senior vice president for operations and the general manager of the SAT Program, said the increase in minority test takers this year pleased the College Board organization.