Having grown up in Iowa City and going to games and being able to read a newspaper I thought maybe.. Just maybe some facts might help in this case. Now I know SID's can play with numbers and unlike Clone or Muskie I didn't take a mental image and count every single person in the stands to show that the facts I am going to present are wrong but here goes.
1970 Iowa 49,728 ISU 27,537 advantage Iowa
1971 Iowa 46,630 ISU 27,805 advantage Iowa
1972 Iowa 44,166 ISU 33,231 advantage Iowa
1973 Iowa 43,569 ISU 31,696 advantage Iowa
1974 Iowa 48,600 ISU 32,419 advantage Iowa
1975 Iowa 53,448 ISU 39,774 advantage Iowa
1976 Iowa 53,465 ISU 40,981 advantage Iowa
1977 Iowa 53,916 ISU 44,060 advantage Iowa
1978 Iowa 53,214 ISU 49,205 advantage Iowa
1979 Iowa 59,708 ISU 45,455 advantage Iowa
Not sure how it will format since I am doing this from my phone so I will summarize 1970 - 1979 it was Iowa 10, ISU zero for average attendance. Please feel free to share your newspaper articles where it says 'in a crowd grossly overstated at 49,263' or 'ISU greatly under reports attendance' etc. Muskie I took advantage of those $2 tickets, sitting under the south end zone bleachers, sitting in any number of seats, sliding down the hill because the game was boring etc. So if you want to run smack you two, attendance smack in the 70's might not be the smack you want to run, unless of course I missed something other than your 'this one time at band camp we all went to the ISU game and there were like 65,000 people there but they only said 27,557 were there but I know way better than that because I counted them all'