That especially looks incredible (if not outright impossible) that since 1990 to 2014, real GDP per capita in the U.S. has increased by 39.8%. And the chart som

That especially looks incredible (if not outright impossible) that since 1990 to 2014, real GDP per capita in the U.S. has increased by 39.8%. And the chart somehow implies that average income remains approximately unchanged. There must be something distorting that chart, like: it is a chart of household income dynamics, and the average size of household has decreased.