CREATE TABLE "population_of_kazakhstan_1939_2009" (
  "year_january" real,
  "population_000" real,
  "rural_pct" real,
  "urban_pct" real,
  "source" text
);

Question: What was the rural % where the source estimate was census and the urban % was larger than 57?
SQL: SELECT SUM("rural_pct") FROM "population_of_kazakhstan_1939_2009" WHERE "source"='estimate' AND "urban_pct">57;