Income inequality in America widened “significantly” last year, according to a U.S. Census Bureau report published today.

A measure of inequality known as the Gini index rose to 0.485 from 0.482 in 2017, according to the bureau’s survey of household finances. The measure compares incomes at the top and bottom of the distribution, and a score of 0 is perfect equality.

The 2018 reading is the first to incorporate the impact of President Donald Trump’s end-2017 tax bill, which was reckoned by many economists to be skewed in favor of the wealthy.

But the distribution of income and wealth in the U.S. has been worsening for decades, making America the most unequal country in the developed world. The trend, which has persisted through recessions and recoveries, and under administrations of both parties, has put inequality at the center of U.S. politics.

Leading candidates for the 2020 Democratic presidential nomination, including senators Elizabeth Warren and Bernie Sanders, are promising to rectify the tilt toward the rich with measures such as taxes on wealth or financial transactions.

Just five states — California, Connecticut, Florida, Louisiana and New York, plus the District of Columbia and Puerto Rico — had Gini indexes higher than the national level, while the reading was lower in 36 states.