I’m not too sure tbh but I would guess covering the rising cost of bills and upkeep of the 3G playing surface, in all honesty.
Given they hand out free season tickets to all, it’s income they’re probably making up from not charging for tickets. £4,819 is equivalent to 482 adult tickets and £8,944 is 895 adult tickets, which given the last attendance was 205 is equivalent to a little over 2 and 4 of those crowds.