In most cases, this is the member's total account balance in the fund. (ato.gov.au)
Some of the firms listed may have additional fees and some firms may reduce or waive commissions or fees, depending on account activity or total account value. (interactivebrokers.com)
As mentioned in the comments, the number of total accounts you have does not have much bearing on your overall credit score. (money.stackexchange.com)