I went to prior to 2010. I went to 08 and 09(the two worst years of D1 football in Fargo) and attendance still was still fine. I dug a little further back and attendance was fine as well, particularly considering how trash their schedules were back then.
If you are talking about the late 90's or early 2000's, yeah. Attendance doesnt look very good relative to nowadays. NDSU has been D1 long enough now and has enough seasons under their belt now to have a pretty accurate baseline of expectations of what sort of crowds will show up. If they can get people to show up during a 7-4 season that followed a 3-8 season which followed a 6-5 season, I'd be very interested in seeing what would have to happen in order to keep people from coming.
I think they got about 12K season ticket holders as well as 3K+ in the student section so just right there the fake attendance requirement would already be satisfied.