Most small businesses choose the calendar year as their fiscal year, but not all. If you are one of these businesses, you're in luck.
As you've noticed, if you choose to view your reports "Yearly", they will default to a calendar year.
To view a different 12 month period you'll want to view the report "monthly" and set the end month as the last in your 12-month period. For example, if your fiscal year is April 1 - March 31, select to view by "monthly" with an end date of "March" This will show you the 12 month period of April through March.