The majority of students in the Flemish Community diagnosed as having special educational needs are educated separately …

„A large proportion of students in the Flemish Community are diagnosed as having special educational needs and the majority of them are educated separately in special schools and classes. […] In 2010, 5.2 % of the total student population in the Flemish Community of Belgium were being educated separately from the mainstream in special schools and classes.“
OECD (Hrsg.), OECD Reviews of School Resources: Flemish Community of Belgium 2015 (2015), S. 43.
Anmerkung: In Österreich etwa 1,5 Prozent.