CREATE TABLE table_80421 ("Year" TEXT, "Carries" FLOAT, "Rushing Yards" FLOAT, "Average" FLOAT, "Touchdowns" FLOAT, "Points" FLOAT)

What is the total number of rushing yards associated with averages over 8.4 and fewer than 54 carries?
SELECT COUNT("Rushing Yards") FROM table_80421 WHERE "Average" > '8.4' AND "Carries" < '54'
SELECT COUNT("Rushing Yards") FROM "table_80421" WHERE "Average" > '8.4' AND "Carries" < '54'