The performance was the weakest since the end of the last recession in 1982, according to government reports. Inflation continued at extremely low levels, with one widely watched price index rising at an annual rate of just 1.8%, the lowest since the spring of 1967. The Commerce Department two months ago estimated growth in the second quarter at 1.1%, revising that to 0.6% last month and again in the current report. Separately, the Commerce Department said after-tax profits of U.S. corporations rose 2.1% in the second quarter instead of the previously estimated 4.1% gain. Profits were down 3% in the first three months of 1986.