CREATE TABLE table_10121 ("Name" TEXT, "Years" TEXT, "Gender" TEXT, "Area" TEXT, "Authority" TEXT, "Decile" FLOAT, "Roll" FLOAT)

How many values for decile occur in Mount Roskill with Monte Cecilia school with a roll greater than 170?
SELECT COUNT("Decile") FROM table_10121 WHERE "Area" = 'mount roskill' AND "Name" = 'monte cecilia school' AND "Roll" > '170'
SELECT COUNT("Decile") FROM "table_10121" WHERE "Area" = 'mount roskill' AND "Name" = 'monte cecilia school' AND "Roll" > '170'