CREATE TABLE table_17381 ("Season" TEXT, "Cup FinalDate" TEXT, "WinningTeam" TEXT, "Score" TEXT, "LosingTeam" TEXT, "Location" TEXT, "Cup Final Attendance" FLOAT)

How many seasons was the losing team Adelaide City?
SELECT COUNT("Season") FROM table_17381 WHERE "LosingTeam" = 'Adelaide City'
SELECT COUNT("Season") FROM "table_17381" WHERE "LosingTeam" = 'Adelaide City'