What is the mother tongue language shared by 300 people in 2006?
CREATE TABLE "mother_tongue_language_2006_and_2011" (
  "mother_tongue" text,
  "population_2006" real,
  "percentage_2006" text,
  "population_2011" real,
  "percentage_2011" text
);
SELECT "mother_tongue" FROM "mother_tongue_language_2006_and_2011" WHERE "population_2006"=300;