What percentage of African government budgets consists of foreign aid (ODA)?

Western governments (sometimes through the IMF and World Bank etc.) structurally give aid money to governments in Africa and other developing regions (Official Development Aid or ODA, which differs from aid given by Oxfam etc. and emergency aid). As a journalist I would like to know how many percent of African government budgets consists of aid from foreign governments? If you can quote examples from specific African countries, I'm also interested. And please list your source. I know in Ethiopia it's about 90%. Many thanks in advance!