CREATE TABLE table_14989 ("Name" TEXT, "Years" TEXT, "Gender" TEXT, "Area" TEXT, "Authority" TEXT, "Decile" FLOAT, "Roll" FLOAT)

How many deciles have an Authority of state and a Name of chertsey school?
SELECT COUNT("Decile") FROM table_14989 WHERE "Authority" = 'state' AND "Name" = 'chertsey school'
SELECT COUNT("Decile") FROM "table_14989" WHERE "Authority" = 'state' AND "Name" = 'chertsey school'