What is the 1994 value with a 2r in 1996, A in 1993, and 2r in 1991?
CREATE TABLE "doubles_performance_timeline" (
  "tournament" text,
  "1990" text,
  "1991" text,
  "1992" text,
  "1993" text,
  "1994" text,
  "1995" text,
  "1996" text
);
SELECT "1994" FROM "doubles_performance_timeline" WHERE "1996"='2r' AND "1993"='a' AND "1991"='2r';