The National Association of Homebuilders said Monday that 24.4 percent of U.S. construction workers were immigrants in 2016, the highest share on record.

But the high percentage of immigrant workers is not because immigrants are taking more jobs, according to the group. Instead, it's because native-born workers are not returning to the sector in the wake of the recession.

A "slow, delayed and reluctant post-recession return of native-born workers underlies the shift towards the higher reliance on immigrants in the construction work force," noted Natalia Siniavskaia, the group's assistant vice president for housing policy research.

The group noted there were 200,000 fewer immigrant construction workers in 2016 than there were during the height of the housing bubble in 2007, according to the NAHB's analysis of Census data. In that year, 22.8 percent of the construction workforce was made up of immigrants.

But the recession also led to the end of 1.7 million jobs for native-born workers, and the vast majority of them — 1.5 million — never returned.

In recent years, the construction industry has begun to struggle to fill positions. Since the end of the recession, total monthly advertised construction job vacancies have quadrupled, according to Labor Department data, but actual hiring has only risen by about a third.

Wages have been rising, but not fast enough to close that gap.

Four out of every five contracting firms believe it will remain difficult or get even harder to recruit and hire new workers in 2018, a Associated General Contractors of America survey released this month found.

The tax cuts passed by the GOP Congress and signed by President Trump are expected to increase demand for construction and, accordingly, for workers, according to the contractors' group.