The New Zealand Knights are a club in another country, where there is no AFL therefore they are not a competitor of AFL and their crowds are irrelevant. The only reason they are in the league was to extend a helping hand to New Zealand football, and the way they are going they are expected to be replaced by an 8th Australian club within a year or two.
Their crowds are an outlier, any statistician could tell you that it would be perfectly acceptable to take their figures out of the equation.
A lot of assumptions in that.....