What was the percentage of muslims during a time where there were 614 registered mosques?
CREATE TABLE "demography_and_ethnic_background" (
  "census_year" real,
  "number_of_muslims_000" real,
  "population_of_england_and_wales_000" real,
  "muslim_pct_of_total_population" text,
  "registered_mosques" real,
  "muslims_per_mosque" real
);
SELECT "muslim_pct_of_total_population" FROM "demography_and_ethnic_background" WHERE "registered_mosques"=614;