I'm not sure about the accuracy of those 1971 numbers. How does a 3-game weekend series against the Yankees go from 25,079 to 6,412 to [unknown]?
Start with Tu, 9/7: 2,369 Detroit 2 - 3
Wed, 9/8: 2,973 Detroit 3 - 5
@Baltimore
@Cleveland
Fri, 9/17: 3,856 Boston 7 - 10
Sat, 9/18: 3,671 Boston 6 - 1
Sun, 9/19: 4,835 Boston 3 - 4
Mon, 9/20: 1,743 Cleveland 1 - 3
Tu, 9/21: 1,311 Cleveland 9 - 1
Wed, 9/22: 1,458 Cleveland 3 - 2
@Boston
Tues, 9/28: 3,242 New York 4 - 2
Wed, 9/29: 4,003 New York 3 - 6
Thu, 9/30 (the end) 14,460 NYY leading 7 - 5 when game called. Nats had 63 wins by forfeiting the last game.