Last Friday, we learned that America’s official unemployment rate, also known as the “U-3” rate, dropped to 3.8 percent in May, its lowest level since April 2000. A broader measure of unemployment, known as the “U-6” rate, also declined, falling from 7.8 percent to 7.6 percent.

The U-6 rate includes, not only people who are looking for a job and can’t find one, but also people who are working part time for economic reasons and people who are only “marginally attached” to the labor force.

In case you’re wondering, the Labor Department defines “marginally attached workers” as “Persons not in the labor force who want and are available for work, and who have looked for a job sometime in the prior 12 months (or since the end of their last job if they held one within the past 12 months), but were not counted as unemployed because they had not searched for work in the 4 weeks preceding the survey.”

At 7.6 percent, the U-6 unemployment rate has reached its lowest level since May 2001. During the economic expansion that lasted from November 2001 to December 2007, the U-6 rate never once fell below 7.9 percent, and it rose as high as 17.1 percent in late 2009 and early 2010, following the Great Recession.