Iowa’s seasonally adjusted unemployment rate dropped to 4 percent in March from 4.1 percent in February, Iowa Workforce Development reported. That’s the lowest rate since May 2008. The state’s jobless rate was 4.4 percent a year ago. The U.S. unemployment rate remained at 5.5 percent in March. “Nonfarm employment increased for the sixth-consecutive month in March, adding 3,300 jobs,” said Iowa Workforce Development Director Beth Townsend. ┬áThe number of unemployed Iowans decreased to 67,800 in March from 70,300 in February. The current estimate is 6,200 lower than the year-ago level of 74,000. The total number of working Iowans increased to 1,647,100 in March. This figure is 600 higher than February and 25,500 higher than last March.