According to a report released Thursday by the state Center for Health Information and Analysis, the median total margin -- the amount of revenues over expenses -- for acute care hospitals in Massachusetts was 3.1 percent in 2016, a drop of 0.7 percentage points from the previous fiscal year. Hospital operations, which do not include things like investment income, showed a similar drop in profitability. Hospitals still did well overall. Of 63 acute hospitals, 47 reported a profit. Twenty-two of 29 parent companies were profitable.