SELECT MIN("Overall") FROM table_39592 WHERE "Downhill" = '1' AND "Season" < '1992'
What is the lowest overall score prior to 1992 with a downhill score of 1?
CREATE TABLE table_39592 (
    "Season" real,
    "Overall" real,
    "Slalom" text,
    "Giant Slalom" real,
    "Super G" real,
    "Downhill" text,
    "Combined" text
)