South Africa= around 55,000,000 of total population (based on 2015 data) Nigeria= around <span>185,000,000 of total population (2015 data) Angola = around </span><span>25,000,000 of total population (2014 data) Congo= around </span><span>82,000,000 of total population (2015 data) Given that there's not an high </span>population growth or <span>birth rate or something like that, I'd say Nigeria </span>