The nation's unemployment rate fell sharply to 5.3 percent in June, the lowest level in 14 years, the Labor Department announced Friday. The improved picture was fueled by an upturn in summer-season hiring among adult men and teenagers. The June jobless rate of 5.3 percent was the lowest figure since May 1974 and dropped three-tenths of a percentage point from the May figure of 5.6 percent, the Labor Department said. The data showed a healthy increase in off-the-farm employment, with some 346,000 more people working in non-farm jobs. (Utah figures on B1.)