William Foege, the director of the CDC in 1983, was quoted in Time Magazine (July 4 1983 issue) as saying the average homosexual AIDS victim had an average of 60 sexual partners in the past 12 months.
And people need to keep in mind that this was not the average for gay men in general. So there would be gay men who had 1 or less partners in a year who would be far less likely to get HIV.