How many stages were won by Robbie McEwen?
CREATE TABLE "jersey_progress" (
  "stage" real,
  "winner" text,
  "general_classification" text,
  "mountains_classification" text,
  "points_classification" text,
  "sprints_classification" text,
  "team_classification" text
);
SELECT COUNT("stage") FROM "jersey_progress" WHERE "winner"='Robbie McEwen';