The Population and stats for Africa have been updated. Check them out at Africa Internet Population. The tables give all the estimates and the graphs help us understand the stats.
For example, the 2015 Q2 Internet Penetration in Africa Graph shows that the average Internet penetration for Africa is 27%, and 48.5% in the rest of the world, not including Africa. Great progress has been made in recent years and the number of Internet users is increasing greatly.