CREATE TABLE table_60613 ("Position" FLOAT, "Team" TEXT, "Played" FLOAT, "Drawn" FLOAT, "Lost" FLOAT, "Goals For" FLOAT, "Goals Against" FLOAT, "Goal Difference" TEXT, "Points 1" TEXT)

What is the goal difference number with a position of 15?
SELECT "Goal Difference" FROM table_60613 WHERE "Position" = '15'
SELECT "Goal Difference" FROM "table_60613" WHERE "Position" = '15'