Question: What is the 1957 number when the 1955 is smaller than 0.63, and 1952 is larger than 0.22?
SQL: SELECT COUNT("1957") FROM "2-18940307-6" WHERE "1955" < 0.63 AND "1952" > 0.22;

Question: What is the 1952 rate when the 1954 is more than 4.2?
SQL: SELECT SUM("1952") FROM "2-18940307-6" WHERE "1954" > 4.2;

Question: What is the 1955 rate when the 1956 is more than 2.9, and 1953 is larger than 4.5?
SQL: SELECT SUM("1955") FROM "2-18940307-6" WHERE "1956" > 2.9 AND "1953" > 4.5;