This shows the total number of cases of AIDS in the USA (second column) in 4 month intervals from 1982. The first column shows the quarter since 1982. Data from "Backcalculation of flexible linear models of the Human Immunodeficiency Virus infection" by P.S. Rosenburg and M.H. Gail, Applied Statistics, Volume 40, 1991, 269-282, Table 1.