If 0.52% is the percentage of the population in chinas tujia what is the overall amount of tujia population?
CREATE TABLE "by_county" (
  "province" text,
  "prefecture" text,
  "county" text,
  "tujia_population" real,
  "pct_of_chinas_tujia_population" text
);
SELECT COUNT("tujia_population") FROM "by_county" WHERE "pct_of_chinas_tujia_population"='0.52%';