FOR OVER A DECADE, Maryland has lagged behind in job growth. Only in the past few months has the state begun to move toward parity with the U.S., according to Economic Pulse, a monthly report published by the Maryland Department of Business & Economic Development. The state now ranks 16th in job growth; last year it placed 38th. The worst year was 1992, when Maryland placed 49th; that was when major companies were making a shift from defense to private-sector work. Other upswing indicators: when compared to comparable months last year, initial claims for unemployment insurance are down 13.6%; AFDC caseloads fell 18.2%; sales of existing homes are up by 14.6%; new housing permits are up by 27.5%; cargo volume at BWI Airport is up 10.9%; and Sun help wanted classifieds are up 12.8%. Baltimore City, as usual, is not faring as well as the neighboring counties, but at least for once its indicators are not declining.