self-employment and ILR

[mush123]

hi,
i'm self-employed (free-lancer) and my fiscal year for annual tax-return is from 31 march to 01 april every year.
i'm going to apply for ilr next month(august) and have one dependent(wife).
To prove my income for my dependent
do i have to show my accountant(business transactions) for last 12 months (25-08-12) to (24-08-13)
or just need to show tax return document of my last fiscal year(31-03-12) to 01-04-13 .
I'm really confused about it
thanks