This is from the African Development Bank:

Findings in the 3^rd edition of the Africa Visa Openness Index Report 2018, published by the African Development Bank and the Africa Union Commission, show that on average African countries are becoming more open to each other. The top 10 and the top 20 most visa-open countries continue to improve their average score, reflecting countries’ more liberal visa policies. In addition, 43 countries improved or maintained their score.

See the whole thing here.