CREATE TABLE table_204_913 (id DECIMAL, "#" DECIMAL, "date" TEXT, "venue" TEXT, "opponent" TEXT, "score" TEXT, "result" TEXT, "competition" TEXT)

what is the number of games played against vietnam ?
SELECT COUNT(*) FROM table_204_913 WHERE "opponent" = 'vietnam'
SELECT COUNT(*) FROM "table_204_913" WHERE "opponent" = 'vietnam'