What is the 1993 value of the French open?
CREATE TABLE "doubles_performance_timeline" (
  "tournament" text,
  "1990" text,
  "1991" text,
  "1992" text,
  "1993" text,
  "1994" text,
  "1995" text,
  "1996" text
);
SELECT "1993" FROM "doubles_performance_timeline" WHERE "tournament"='french open';