"The number of children and youth ages 3–21 receiving special education services was 6.4 million, or about 13 percent of all public school students, in 2012–13. Some 35 percent of students receiving special education services had specific learning disabilities."
"In school year 2012–13, a higher percentage of children and youth ages 3–21 received special education services under IDEA for specific learning disabilities than for any other type of disability. A specific learning disability is a disorder in one or more of the basic psychological processes involved in understanding or using language, spoken or written, that may manifest itself in an imperfect ability to listen, think, speak, read, write, spell, or do mathematical calculations. In 2012–13, some 35 percent of all children and youth receiving special education services had specific learning disabilities, 21 percent had speech or language impairments, and 12 percent had other health impairments (including having limited strength, vitality, or alertness due to chronic or acute health problems such as a heart condition, tuberculosis, rheumatic fever, nephritis, asthma, sickle cell anemia, hemophilia, epilepsy, lead poisoning, leukemia, or diabetes). Children and youth with autism, intellectual disabilities, developmental delays, or emotional disturbances each accounted for between 6 and 8 percent of students served under IDEA. Children and youth with multiple disabilities, hearing impairments, orthopedic impairments, visual impairments, traumatic brain injuries, or deaf-blindness each accounted for 2 percent or less of those served under IDEA."