Нормативов нет. Есть рекомендации минобраhttp://www.google.ru/url?sa=t&source=web&cd=8&ved=0CEoQFjAH&url=http%3A%2F%2Fipkps.bsu.edu.ru%2Fsource%2Fmetod_sluzva%2Fnach%2Fnormativ.rtf&rct=j&q=%D0%BA%D0%BE%D0%BD%D1%82%D1%80%D0%BE%D0%BB%D1%8C%20%D0%B8%20%D0%BE%D1%86%D0%B5%D0%BD%D0%BA%D0%B0%20%D1%80%D0%B5%D0%B7%D1%83%D0%BB%D1%8C%D1%82%D0%B0%D1%82%D0%BE%D0%B2%20%D0%BE%D0%B1%D1%83%D1%87%D0%B5%D0%BD%D0%B8%D1%8F.%20%D0%9C%D0%B5%D1%82%D0%BE%D0%B4%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B8%D0%B5%20%D1%80%D0%B5%D0%BA%D0%BE%D0%BC%D0%B5%D0%BD%D0%B4%D0%B0%D1%86%D0%B8%D0%B8&ei=lpmKToflHYvHtAbOlcGxAg&usg=AFQjCNGuXeAcuJhVhqH_swQyfwky2Q-4XA&sig2=jBbElF7qGKqZXkrwc8LUfg&cad=rjt