Theoretically, parents shouldn't be more than 40 years of age. The vast majority of people who today have children attending primary and secondary schools are roughly perhaps 45 years old. Since education has been mandatory since 1970, if I'm not mistaken, that means that, if they started in 1970, some parents are 37 years old. The percentage of illiterate parents that you're telling us about should be very low compared to the children who do not have any support at home.
