A total of 91 corporations in the Fortune 500, many worth billions of dollars, paid no federal taxes last year, the Washington Post reported Monday.

About 400 of America’s largest corporations paid an average federal tax rate of about 11 percent on their profits last year, roughly half the official rate established under President Donald Trump’s 2017 tax law.

“Profitable American corporations in 2018 collectively paid an average effective federal income tax rate of 11.3 percent on their 2018 income, barely more than half the 21 percent statutory tax rate,” said the report from Institute on Taxation and Economic Policy.

In fairness, analysts say the phenomenon is nothing new. Some companies have long paid less than official rates for a variety of reasons.

As Kiplinger reported last month as the federal Tax Cuts and Jobs Act approached its two-year anniversary, the act is just one factor in the tax landscape for America’s biggest firms.

Still, Kiplinger reported many of the nation’s largest companies have lower tax rates than most citizens.

The TCJA, signed by President Donald Trump in late 2017, permanently lowered the federal corporate tax rate to 21% from 35%. Analysts say many companies are paying even less.