The nation’s economy is entering 2015 in its best shape since the recession, but the improving job market has so far failed to help most Americans earn significantly more at work.

On Friday, the Labor Department reported that employers added another 252,000 workers to their payrolls in December, capping a year in which total employment rose by 2.95 million, the largest advance since 1999.

The unemployment rate also improved, edging down last month to 5.6 percent from 5.8 percent in November. The rate plunged just over a full percentage point between 2013 and 2014, the largest decline since 1984.