An emerging economic recovery and good news about COVID-19 pushed business confidence slightly higher in Massachusetts during May. The Associated Industries of Massachusetts (AIM) Business Confidence Index rose 1.2 points to 61.9 last month, leaving it almost 20 points higher than a year ago. Confidence levels remain comfortably in optimistic territory. The increase was the fourth in five months and came as Massachusetts Gov. Charlie Baker announced the resumption of full business activity in the Commonwealth. The federal government also said vaccinated people no longer need to wear masks in most public settings.