Secondary education in Norway is primarily based on public schools: In 2007, 93% of upper secondary school students attended public schools.[7] Until 2005, Norwegian law held private secondary schools to be illegal unless they offered a "religious or pedagogic alternative", so the only private schools in existence were religious (Christian), Steiner/Waldorf, Montessori schools, and Danielsen. The first "standard" private upper secondary schools opened in the fall of 2005.