It depends on private in which sense. The Netherlands has "freedom of education" and equal funding for public and private schools. As long as you can get enough

It depends on private in which sense. The Netherlands has "freedom of education" and equal funding for public and private schools. As long as you can get enough interest and meet quality criteria, you can start a private school and get public funding for it. Additionally, there are some (but very few) private schools which don't take government funding and emphasize small class rooms, etc. Typically only the truly rich kids go to private schools, and only when they have difficulty achieving the standards parents want :)