What is the 1955 rate when the 1956 is more than 2.9, and 1953 is larger than 4.5?
CREATE TABLE "1950s" (
  "country" text,
  "1951" real,
  "1952" real,
  "1953" real,
  "1954" real,
  "1955" real,
  "1956" real,
  "1957" real,
  "1958" real,
  "1959" real
);
SELECT SUM("1955") FROM "1950s" WHERE "1956">2.9 AND "1953">4.5;