CREATE TABLE table_20613 ("Missouri vs." TEXT, "Overall Record" TEXT, "at Columbia" TEXT, "at Opponents Venue" TEXT, "at Neutral Site" TEXT, "Last 5 Meetings" TEXT, "Last 10 Meetings" TEXT, "Current Streak" TEXT, "During Time in Big 12" TEXT)

Name the total number of opponets venue for oklahoma
SELECT COUNT("at Opponents Venue") FROM table_20613 WHERE "Missouri vs." = 'Oklahoma'
SELECT COUNT("at Opponents Venue") FROM "table_20613" WHERE "Missouri vs." = 'Oklahoma'