The data, which measured how Americans were doing six years into the economic recovery, show that incomes in the middle, measured in 2015 dollars, were still 1.6 percent below the previous peak of $57,423 a household, which was attained in 2007, just before the economy sank into what has come to be known as the Great Recession.

How does that look compared to the nation’s recent history? After the economy slipped into recession in 1969, it took only three years for incomes in the middle to rebound and surpass their previous peak. After the downturn of 1973, it took five; after back-to-back recessions in 1981 and 1982, it took seven.

And, except for the long expansion that ran from 1991 through 2000, it has been getting worse. The economic growth from late 2001 to about the end of 2007 never even managed to deliver incomes above the previous peak for the typical household, reached near the end of Bill Clinton’s presidency. The expansion underway today may not get there, either.

Today, median household incomes are still 2.4 percent below the absolute peak they hit in 1999 — when Facebook had yet to come into existence, the big news in the music business was Napster, and the good times in Silicon Valley were about to come crashing down with the collapse of the dot-com bubble.

At the bottom of the ladder, households at the 10th percentile — those poorer than 90 percent of the population — are still a bit poorer than they were in 1989. Americans have managed to develop an internet economy, invent social media and build driverless cars since then, but not to improve the lot of those at the bottom.

What’s more, changes starting in 2013 in the way the census asks people about their incomes can distort comparisons with previous years. After adjusting the data for these changes, according to Elise Gould of the Economic Policy Institute, the income of American households in the middle of the distribution last year was still 4.6 percent below its level in 2007 and 5.4 percent below where it was in 1999.