CREATE TABLE table_72664 ("Year" FLOAT, "Dates" TEXT, "Champion" TEXT, "Country" TEXT, "Score" TEXT, "To par" TEXT, "Margin of victory" TEXT, "Purse  (  US$  ) " FLOAT, "Winners share" FLOAT)

How many dollars is the purse when the margin of victory is 8 strokes?
SELECT COUNT("Purse ( US$ )") FROM table_72664 WHERE "Margin of victory" = '8 strokes'
SELECT COUNT("Purse ( US$ )") FROM "table_72664" WHERE "Margin of victory" = '8 strokes'