Ghana scored 1 on the UNESCO Gender Parity Index (GPI) for Primary and Secondary school levels in 2013. The adult literacy rate in Ghana was 79.04% in 2018, with males at 78.3% and females at 65.3%. Ghana's rapid shift from an informal economy to a formal economy made education an important political objective. The magnitude of the task, as well as economic difficulties and political instabilities, have slowed down attempted reforms. The Education Act of 1987, followed by the Constitution of 1992, gave a new impulse to educational policies in the country. In 2011, the primary school net enrollment rate was 84%, described by UNICEF as "far ahead" of the sub-Saharan average. In its 2013–14 report, the World Economic Forum ranked Ghana 46th out of 148 countries for education system quality. In 2010, Ghana's literacy rate was 71.5%, with a notable gap between men (78.3%) and women (65.3%). The Guardian newspaper disclosed in April 2015 that 90% of children in Ghana were enrolled in school, ahead of countries like Pakistan and Nigeria at 72% and 64% respectively. The literacy rate of males and females aged 15–24 in Ghana was 81% in 2010, with males at 82%, and females at 80%.