This chart represents a plot of two sets of numbers. The actual figures for the period a reproduced below. The purpose of all of this is to understand the effect of inflation on real growth.
Inflation is the devaluation of the buying power of the dollar.
For certain years, during the nineteen eighties, we endured double-digit inflation. This may also be the biggest scam ever put over on the American people. Figure it out for yourself. You do not have to be a rocket scientist to do this. Seventh grade math, at the most, is all you need.