Comment by pseudohadamard

That's true but a bit misleading. In 1975 China had a vast population and was at the tail end of decades of Maoist mismanagement, so the per capita income was very low. Zambia OTOH was still in the ten-year honeymoon period after independence where established institutions mostly functioned and the country had enormous mineral wealth, so things ran OK for awhile even under UNIP one-party rule... and then went downhill rapidly. Graphs of per capita GDP for the two countries would look something like an X, Zambia being the line going down, China being the one going up.