CREATE TABLE table_73423 ("Year" FLOAT, "Date" TEXT, "Driver" TEXT, "Team" TEXT, "Manufacturer" TEXT, "Laps" TEXT, "Miles  ( km ) " TEXT, "Race Time" TEXT, "Average Speed  ( mph ) " TEXT, "Report" TEXT)

How many races did Cale Yarborough win at an average speed of 88.924 mph?
SELECT COUNT("Race Time") FROM table_73423 WHERE "Driver" = 'Cale Yarborough' AND "Average Speed (mph)" = '88.924'
SELECT COUNT("Race Time") FROM "table_73423" WHERE "Average Speed (mph)" = '88.924' AND "Driver" = 'Cale Yarborough'