I think You should sit quietly because 18k attendance in 2nd match looks like bug ;-) Take it as unexpected bonus and consider 15k as typical attendance.
Before Your 2nd home match You won by 76 points, before 3rd match You won only by 27 points. It's well known that last match has the highest impact, and before 2nd home match fans were much happier, maybe there were few other smaller factors which accumulated.