Historically and globally boys and men have been the first to receive education and become literate, and women and girls have been the last to have access and the first to have their human right to education taken away, or interrupted as was & is being tried under the Taliban in Afghanistan.
England in 16th century was thought to be rather advanced in educating girls as well as boys though there was definitely a class bias, and women have in general been given only gradual admittance to the full mysteries of education. At my own Cambridge College founded in 1873 women were allowed to sit the exams but were not granted a degree until 1948.
An estimated 23% of women in the world today are illiterate as compared 13% with men (www.dfid.gov.uk). Many of these women & men are in older age groups as enrolment rates for both girls and boys has increased greatly in recent decades all over the world. Whilst many countries have achieved gender parity at primary and secondary levels however there are often many fewer girls in universities and colleges, and in vocational training or other types of continuing education.
Girls may be pushed or pulled out of school earlier for a variety of reasons, though the underlying basis is the same perception that education and a professional career are secondary for women.
Girls may be taken out of school in order to get married, to help on the family farm, or to work in the garment industry or in some other type of new activity supported by Foreign Direct Investment (FDI) which requires little training & is poorly paid and insecure.
There are also cases however where boys are pulled out of school earlier to get ahead making money, often in some
semi-legal way, and girls are left in the education system usually to enter civil service jobs which do not require a high level of specialized knowledge. This is the situation for several Caribbean countries where women dominate the civil service, but many aspects of commerce and trade, including the very lucrative drugs trade, are largely male- dominated.(unicef.org/lac/English_10622.htm)