At least one-quarter, I'd suggest. A 25% discount on the 16,098 average would mean 12,074.
Consider that announced attendance of 16,722 Wednesday meant the Izod Center was 83.7% full (capacity 19,968), but I estimated the arena was at best 60% full. That would mean 11,980, or a more than 25% smaller crowd. But let's just take 25% off 16,722 and call it 12,542.
Well, at last night's game with the Toronto Raptors, the attendance was announced at 13,926, or 69.7% full. Apply the 25% fudge factor and we get 10,452, or 52.3% full.
Given photos like this and this of the crowd, that seems far more realistic--even generous.