CREATE TABLE table_63249 ("Date" TEXT, "Opponent" TEXT, "Venue" TEXT, "Result" TEXT, "Attendance" FLOAT)

What is the number of attendance values for ties having an opponent of Middlesbrough and result of 3-1?
SELECT COUNT("Attendance") FROM table_63249 WHERE "Opponent" = 'middlesbrough' AND "Result" = '3-1'
SELECT COUNT("Attendance") FROM "table_63249" WHERE "Opponent" = 'middlesbrough' AND "Result" = '3-1'