What is 2000, when 1996 is "A", when 1997 is "A", and when 2007 is "A"?
CREATE TABLE "singles_performance_timeline" (
  "tournament" text,
  "1993" text,
  "1994" text,
  "1995" text,
  "1996" text,
  "1997" text,
  "1998" text,
  "1999" text,
  "2000" text,
  "2001" text,
  "2002" text,
  "2003" text,
  "2004" text,
  "2005" text,
  "2006" text,
  "2007" text,
  "career_wr" text,
  "career_win_loss" text
);
SELECT "2000" FROM "singles_performance_timeline" WHERE "1996"='a' AND "1997"='a' AND "2007"='a';