The crowd numbers in Port Moresby depend very much on which teams are coming into play.
Even-though the Vipers represent the City and the Port Moresby Rugby Football League, most city residents will first and foremost support the Team that is flying in from their home Provinces.
Teams like the Rabaul Gurias, Goroka Lahanis and the Mt Hagen Eagles attract more fans when they come to play in Port Moresby. Last weekend there was a double header in Port Moresby involving the Gurias and the Mioks who had flown in to play against the City based Vipers and Isou respectively. I can't remember the crowd now but it was just below 4000.
Back in the Provinces the numbers will vary. The Gurias get between 5K-7K every home game in Kokopo and the same for Lae Tigers at their home ground in Lae.
The Highlands Provinces probably 3K-5K and this depends on capacity and also the visiting Team.