Education in New Zealand pursues three-tier model which includes primary schools, followed by secondary schools (High Schools) and tertiary education at universities and polytechs. The education of New Zealand ranks as 7th best in the world by “Program for International Student Assessment”. The Education Index is published with UN’s Human Development Index in 2008 based on data from 2006 lists New Zealand as 0.993 amongst highest in world tied for first with Denmark, Finland and Australia. Education is free and obligatory for age between 6 and 16 but children normally start school on their 5th birthday or first school day after it. Post obligatory education is synchronized within “New Zealand Qualification Framework” a unified system of national qualification in schools, vocational education and training.