How many cities were there in 2012 where the rate of burglary was 224.8?
CREATE TABLE "2012_calendar_year_ratios_of_crime_per_1" (
  "state" text,
  "city" text,
  "population" real,
  "violent_crime" text,
  "murder_and_non_negligent_manslaughter" text,
  "forcible_rape" text,
  "robbery" text,
  "aggravated_assault" text,
  "property_crime" text,
  "burglary" text,
  "larceny_theft" text,
  "motor_vehicle_theft" text
);
SELECT COUNT("property_crime") FROM "2012_calendar_year_ratios_of_crime_per_1" WHERE "burglary"='224.8';