What is the 2010 result of a tournament that is A in 2006 and A in 2011?
CREATE TABLE "singles_performance_timeline" (
  "tournament" text,
  "2006" text,
  "2007" text,
  "2008" text,
  "2009" text,
  "2010" text,
  "2011" text,
  "2012" text
);
SELECT "2010" FROM "singles_performance_timeline" WHERE "2011"='a' AND "2006"='a';