SELECT COUNT("Winner") FROM table_27792 WHERE "Stage" = '5'
How many winners were there for stage 5?
CREATE TABLE table_27792 (
    "Stage" real,
    "Winner" text,
    "General Classification" text,
    "Mountains Classification" text,
    "Sprint Classification" text,
    "Young Rider Classification" text,
    "Team Classification" text,
    "Aggressive Rider" text
)