According to 2013 data, less than a third of poor Nigerian children between 15 and 17 years of age had entered primary school at the correct time, though nearly all of the children from richer households had (see Figure 2.5). The gap continues to widen at the start of each level of education, as greater proportions of poor children drop out. By the start of upper secondary education, only 7 per cent of poor children enter school, compared to 80 per cent of wealthier children.