The world's literacy rate has increase from 66.7% in 1979 to 86.3% today. Lower literacy rates contribute the most to poverty

 The world's literacy rate has increased dramatically in the last 40 years, from 66.7% in 1979 to 86.3% today.^[3] Lower literacy levels are mostly attributable to poverty^{[citation needed]}. Lower literacy rates are mostly found in South Asia and Sub-Saharan Africa.^[4] The world's largest ethnic group is Han Chinese, with Mandarin being the world's most spoken language in terms of native speakers.

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https://en.wikipedia.org/wiki/Demographics_of_the_world