The St. Louis Fed post, Healthier Countries, if Not Wealthier Countries by Guillaume Vandenbroucke (12/26/2019) notes
The income gap between rich and poor countries doesn’t seem to be closing. In fact, it seems to be getting wider. However, the gaps between these groups of countries when it comes to health may indeed be narrowing.
For example, the graph copied here provides time series of GDP of high-income countries and Sub-Saharan African countries. The gap between the two cohorts has grown. Yet,
Not surprisingly, sub-Saharan African countries exhibit a lower life expectancy at birth and a higher crude death rate than the high-income countries. What is surprising, however, is that these measures of health are converging to that of the rich countries, unlike GDP per capita.
There are two other graphs in the post. The data is from the world bank and can be found.