For most high-income countries of the world, GDP over time.

For most high-income countries of the world, GDP HAS INCREASED GRADUALLY over time.

Explanation:

Both GDP and GDP per capita has increased for almost all high income countries. Actually the only country in the world that was once rich and had a very high GDP and GDP per capita that turned into a developing country (AKA poor country) is Argentina. It is a unique case in all the world, since Argentina had the highest GDP per capita for 2 years (1895 and 1896) and continued to have a relatively high GDP per capita more than 60 years. Then political turmoil and corruption resulting in it falling from number one spot to number 73.

answer; coefficient of correlation;

answer(c) factors of production;