Bulloch County students earned higher marks on the SAT college admission test this year, but mostly lagged behind state and national averages, according to data for the Class of 2013 released Thursday. Graduating students in the district’s three high schools scored an average 1417 out of a possible 2400, 13 points more than the mean score of last year’s test takers. Scores in subject areas tested — critical reading, math and writing, each scored on an 800-point scale — rose, slightly, throughout the district.