The US four-week moving average of initial claims for unemployment insurance edged down to 224,500 last week, a decrease 500 from the previous week’s average, the US Department of Labor reported. The previous week’s average was revised upward by 1,250.

The four-week moving average decreases the volatility of the weekly numbers. Total initial claims for unemployment insurance for the week ended March 24 fell to 215,000, down 12,000 from the previous week’s level, which was revised downward by 2,000. This is the lowest level for initial claims since Jan. 27, 1973, when it was 214,000.

Last week’s report reflects the annual revision to the weekly unemployment claims seasonal adjustment factors. The seasonal adjustment factors used for the weekly claims data from 2013 forward, along with the resulting seasonally adjusted values for initial claims and continuing claims, have been revised.

This report reflects the department’s annual revision to the weekly unemployment claims seasonal adjustment factor. The seasonal adjustment factors used for the Unemployment Insurance Weekly Claims data from 2013 forward, along with the resulting seasonally adjusted values for initial claims and continuing claims, have been revised.

Claims-taking procedures in Puerto Rico and in the Virgin Islands have still not returned to normal.