Schools suspend minority students at much higher rates than their peers, sometimes starting from preschool.

The Civil Rights Data Collection, a national survey conducted by the U.S. Department of Education, gathered information on more than 50 million students at more than 95,000 schools and found that although suspensions decreased by nearly 20 percentage points between the 2011-12 and 2013-14 school years, gaps between the suspension rates of different groups remained.

The survey included 1,439,188 preschool students in 28,783 schools. Of those, 6,743, or 0.47 percent, were suspended once or more than once.

While black girls represent 20 percent of preschool enrollment, 54 percent of preschool girls suspended once or more were black. And black preschool children overall were 3.6 times as likely to be suspended as young white kids.

The results don't "paint a very good picture," said Liz King, senior policy analyst at the Leadership for Civil and Human Rights.

Across all grades, 2.8 million students were suspended once or more than once. Black students were nearly four times as likely to be suspended and nearly twice as likely to be expelled as white students. Students with disabilities were also twice as likely to be suspended.

The disparity "tears at the moral fabric of the nation," said U.S. Secretary of Education John B. King Jr. "We will not compromise away the civil right of all students to an excellent education."