CREATE TABLE table_20315 ("Series" TEXT, "Episodes" FLOAT, "Series premiere" TEXT, "Series finale" TEXT, "Region 1" TEXT, "Region 2" TEXT, "Region 4" TEXT)

How many episodes in the series that premieres 5 february 2012
SELECT "Episodes" FROM table_20315 WHERE "Series premiere" = '5 February 2012'
SELECT "Episodes" FROM "table_20315" WHERE "Series premiere" = '5 February 2012'