Hello Cory,
Where do you have placed the sub Report and have you linked the sub report so that whenever that sub report gets executed for an year its should run for that specific Year only.
Can you check if you have some conditions on sub report like
Year({SALES.SALES_DATE})={?@Year}.
How mush data you have in the system?
Could you please share the screen shot of the CR in Design mode?
Regards
Niraj