What is the name of the member country that has a Population of 1,341,664?
CREATE TABLE "2004_enlargement" (
  "member_countries" text,
  "population" text,
  "area_km" text,
  "gdp_billion_us" text,
  "gdp_per_capita_us" text
);
SELECT "member_countries" FROM "2004_enlargement" WHERE "population"='1,341,664';