CREATE TABLE table_10408617_5 (tariff_code VARCHAR, bts_retail_price__regulated_ VARCHAR)

How many tariff codes have a bts retail price of 2.553p/min?
SELECT COUNT(tariff_code) FROM table_10408617_5 WHERE bts_retail_price__regulated_ = "2.553p/min"
SELECT COUNT("tariff_code") FROM "table_10408617_5" WHERE "2.553p/min" = "bts_retail_price__regulated_"