Maine’s unemployment rate continues to improve, setting a new record low in March when only 3 percent of Mainers seeking jobs were without one.

Nationally, the rate was at 4.5 percent.

The initial estimate of nonfarm payroll jobs in March reached 623,000, a new high. That’s up by 5,300 from this time last year, statistics released Friday by the Maine Department of Labor showed.

The labor force participation rate is also up to 63.9 percent, above the national average. It hasn’t been that high in Maine since the summer of 2014.

Maine’s labor force participation rate — basically a picture of how many people are actively engaged in the labor market — was at its low point in 1978 when it dipped below 60 percent. Its high came in 1992 when it nearly reached 69 percent.

Private sector jobs totaled 523,200, also a new high, with the biggest gains coming in construction, trade, utilities, transportation, education and health care.

The 99,800 jobs in federal, state and local governments is the same as last year, making up 16 percent of nonfarm jobs in Maine, the lowest percentage on record.

New Hampshire is the only New England state to post a lower unemployment rate. It was at 2.8 percent in March. Vermont and Maine were tied. Connecticut trailed the rest of the region at 4.8 percent unemployment.

In Androscoggin County, unemployment topped out at more than 11 percent back in 1991. Its post-recession high in 2010 hit 9.3 percent. It’s now at 3.2 percent, down from 4.2 this time last year.

Economists generally consider 4 percent unemployment a natural benchmark because there are always people who are between jobs, not necessarily unable to find them.