The literacy rate (the amount of the adult population who can read or write) of Niger is among the lowest in the world. In 2005 it was estimated to be only 28.7% (42.9% male and 15.1% female). Primary education in Niger is required for six years. The primary school enrollment and attendance rates are low, particularly for girls. Children are often made to work rather than attend school. This is particularly true during planting or harvest periods.