Guessing from context in the document, I'd say circa 1982. > "Some five years ago, Jim Simons ... persuaded me to come down and consult for a day in March 1977

Guessing from context in the document, I'd say circa 1982. > "Some five years ago, Jim Simons ... persuaded me to come down and consult for a day in March 1977." Also, the latest figures for reported returns in the document are dated April 1981–March 1982, so that's consistent.