By late 2012, roughly 50 million native-born working-age Americans weren’t working, up from 40 million in 2000, according to the March 13 report, titled “Still No Evidence of a Labor Shortage.”

The army of idle Americans is important for the immigration debate, because advocates for greater immigration say foreign workers are needed to fill slots that can’t be taken by Americans.

But the government data shows that 16.7 million native-born Americans wanted — but did not have — full-time work in 2013, up from 10.5 million in late 2007, and 7.8 million in 2000.

These unemployment and underemployment numbers include all native-born Americans who sought work in the last few weeks, are working part-time while seeking full-time jobs, and those who are “marginally attached” to the workforce.