CREATE TABLE table_55436 ("Date" TEXT, "Opponent" TEXT, "Venue" TEXT, "Result" TEXT, "Attendance" FLOAT)

What is the lowest Attendance when Middlesbrough played at Venue A?
SELECT MIN("Attendance") FROM table_55436 WHERE "Opponent" = 'middlesbrough' AND "Venue" = 'a'
SELECT MIN("Attendance") FROM "table_55436" WHERE "Opponent" = 'middlesbrough' AND "Venue" = 'a'