A smaller percentage of Americans in the unemployment line received benefits in 1990 than during any other recession year since World War II, according to a report released today.

Only 37 percent of the nation's jobless received unemployment benefits in an average month in 1990, said a study by the Center on Budget and Policy Priorities, a labor-backed research organization that studies government social programs.That was a record low for the percentage of people receiving unemployment help for a year in which the U.S. economy was in a recession, the report said. "This low level of protection . . . is unparalleled," it said.

During 1975, for instance, when the country also was in a recession, 75 percent of the nation's unemployed received benefits, the report said.

Meanwhile, the Labor Department said the number of people filing new unemployment claims rose to 543,000 in the week ending March 23 - the highest one-week level since January 1983.