CREATE TABLE table_57830 ("Name" TEXT, "Years" TEXT, "Gender" TEXT, "Area" TEXT, "Authority" TEXT, "Decile" FLOAT, "Roll" FLOAT)

For the roll of 651, what was the lowest Decile?
SELECT MIN("Decile") FROM table_57830 WHERE "Roll" = '651'
SELECT MIN("Decile") FROM "table_57830" WHERE "Roll" = '651'