There are 39 pages in the Labor Department’s February report on the employment situation in the United States, but they can be summed up in four words: The economy is humming.

The 313,000 jobs that the nation added in February are far more than are needed to keep up with population growth and continue a surprising burst of job creation to start the year. In the first two months of 2018, the economy has added an average of 276,000 jobs a month, a big step up from 182,000 on average in 2017.

This is not the kind of data you expect in an expansion that is nine years old, or out of a labor market that is already at full employment. It suggests that employers are filling jobs not merely from people they’ve poached from competitors, but also from more people who have entered the work force. And other data in the latest report matches that idea.

The number of adults not in the labor force fell by a whopping 653,000 people, as the participation rate — the proportion of adults who either have a job or are looking for one — rose a healthy 0.3 percent to 63 percent. The proportion of people in their prime working years (25 to 54) who are working is at its highest level since 2008.