1990-1998 volumes: 31, 29-30, 28, 27, 26, 25, 24, 231980-1989 volumes: 22, 21, 20, 19, 18, 17, 15, 16, 14, 131970-1979 volumes: 12, 11, 10, 9, 8, 7, 6, 5, 4, 31960-1969 volumes: 2, 1