According to Los Angeles Times, ratings from 1982 to 1983 were based on 83.3 million households with at least one television set.
"Television Ratings" column list is located at Part VI, "Calendar" section.
Below sources originated from Los Angeles Times, republished in microfilm copies, which may be located in your local library.
According to the Daily Breeze, a newspaper from Torrance, California, the 1985–86 ratings are based on 85.9 million households with at least one television.
According to many newspapers, including the main source USA Today, the 1989–90 Nielsen ratings are based on 92.1 million households that have at least one television.