CREATE TABLE table_71747 ("Year" FLOAT, "Opponent" TEXT, "Competition" TEXT, "Score" TEXT, "Venue" TEXT, "Attendance" TEXT)

What year was the average attendance 80,388?
SELECT AVG("Year") FROM table_71747 WHERE "Attendance" = '80,388'
SELECT AVG("Year") FROM "table_71747" WHERE "Attendance" = '80,388'