Figure 3. The adults illiteracy rate is another of the elements of the Human Development Index of the UN which
correlates clearly with the PCI. Obtaining a rate under 10% implies rising the PCI over 4000 US$. There are,
though, wide differences for the same level of income. The higher rates generally correspond to Muslim countries
with very high rates of women illiteracy due to the existing discrimination; the lower rates corresponds to current
or past socialist countries.