How many times was the GFR 2006 equal to 53.2?
CREATE TABLE "references" (
  "county" text,
  "live_births_2006" real,
  "gfr_2006" text,
  "tfr_2006" text,
  "whites_as_pct_of_pop" text
);
SELECT COUNT("whites_as_pct_of_pop") FROM "references" WHERE "gfr_2006"='53.2';