FAFSA, my parents filed their taxes jointly, what do I do?

There's a question for how much my father earned and how much my mother earned but they filed their taxes jointly, what do I do now? Do I split the earnings and put half in one and half in the other? Do I put in 0 for my dad and all the income for my mom (she's the one that works)? Or do I just put in the total amount for each?