Educational lag is costly for the education systems of the region. Even bearing in mind that several countries have automatic promotion systems for the first few grades, by 9-11 years of age there is already a significant percentage of children who are two or more years behind the grade they should be in (see figure II.3. According to UNESCO, in the period 2007-2008 the overall percentage of repeaters for all primary education grades was 3.8% and the drop-out rates for grades one through six were 3.7%, 1.7%, 2.0%, 1.5% and 2.8% respectively (UNESCO, 2010b). In 2006-2007, nearly 3 million children were not in school. Primary education completion rates are 96% in urban areas but only 85% in rural areas.