The billionaire class — the country’s top 0.01 percent of earners — have enjoyed more than 15 times as much wage growth as America’s working and middle class since 1979, new wage data reveals.

Between 1979 and 2017, the wages of the bottom 90 percent — the country’s working and lower middle class — have grown by only about 22 percent, Economic Policy Institute (EPI) researchers find.

Compare that small wage increase over nearly four decades to the booming wage growth of America’s top one percent, who have seen their wages grow more than 155 percent during the same period.

The top 0.01 percent — the country’s billionaire class — saw their wages grow by more than 343 percent in the last four decades, more than 15 times the wage growth of the bottom 90 percent of Americans.

In 1979, America’s working class was earning on average about $29,600 a year. Fast forward to 2017, and the same bottom 90 percent of Americans are earning only about $6,600 more annually.

The almost four decades of wage stagnation among the country’s working and middle class comes as the national immigration policy has allowed for the admission of more than 1.5 million mostly low-skilled immigrants every year.

In the last decade, alone, the U.S. admitted ten million legal immigrants, forcing American workers to compete against a growing population of low-wage workers. Meanwhile, employers are able to reduce wages and drive up their profit margins thanks to the annual low-skilled immigration scheme.

The Washington, DC-imposed mass immigration policy is a boon to corporate executives, Wall Street, big business, and multinational conglomerates as every one percent increase in the immigrant composition of an occupation’s labor force reduces Americans’ hourly wages by 0.4 percent. Every one percent increase in the immigrant workforce reduces Americans’ overall wages by 0.8 percent.