Gender Parity Index, Literacy Rate, Ages 15-24 (Ratio)
Definition :

Ratio of young literacy rate, female to young literacy rate, male.

Explanation :

A GPI of 1 indicates parity between the sexes; a GPI that varies between 0 and 1 typically means a disparity in favour of males; whereas a GPI greater than 1 indicates a disparity in favour of females.