CREATE TABLE table_15210 ("Date" TEXT, "Visitor" TEXT, "Score" TEXT, "Home" TEXT, "Decision" TEXT, "Attendance" FLOAT, "Record" TEXT)

Record of 18 15 6 belongs to what lowest attendance?
SELECT MIN("Attendance") FROM table_15210 WHERE "Record" = '18–15–6'
SELECT MIN("Attendance") FROM "table_15210" WHERE "Record" = '18–15–6'