I have a formula that I'd like to have increment by one, but I can't figure out how to do it.

Here's the formula:
=IF(INDIRECT("'Supervisor'!B"&ROW()-4)="Y",E12-D12,IF(INDIRECT("'Supervisor'!B"&ROW()-4)="N","0",IF(INDIRECT('"Supervisor'!B&ROW()-4)="","0")))

I'd like to have the -4 in the equation increment to -5 when I paste it to the next row without having to fix each one of them. Any ideas?