CREATE TABLE table_44 ("Scheme" TEXT, "Tariff code" TEXT, "BTs retail price  ( regulated ) " TEXT, "Approx premium" TEXT, "Prefixes" TEXT)

How many tariff codes have a bts retail price of 2.553p/min?
SELECT COUNT("Tariff code") FROM table_44 WHERE "BTs retail price (regulated)" = '2.553p/min'
SELECT COUNT("Tariff code") FROM "table_44" WHERE "BTs retail price (regulated)" = '2.553p/min'