CREATE TABLE table_68265 ("Name" CLOB, "Years" CLOB, "Gender" CLOB, "Area" CLOB, "Authority" CLOB, "Decile" FLOAT, "Roll" FLOAT)

tell me the total number of decile with a roll showing 251.
SELECT COUNT("Decile") FROM table_68265 WHERE "Roll" = '251'
SELECT COUNT("Decile") FROM "table_68265" WHERE "Roll" = '251'