Since 1970 single-parent households have increased among non-Hispanic whites, Hispanics, and blacks.  In 1970, 12 percent of all non-Hispanic white families were headed by a single parent, but by 1990 the percentage had risen to 22.  For Hispanics the change was from 10 to 27 percent, and for blacks it rose from 33 percent to 56 percent.  Most single-parent families continue to be headed by females.  Nonetheless, since 1970 among non-Hispanic whites the share of single-parent families headed by males rose from 17 percent to 23 percent for Hispanics from 14 to 26.  There was no significant change for blacks, the share rising from 12 to 13 percent.
    Counties with high percentages of single-person households usually also have high percentages of aged or high percentages of students or military personnel.