Mortgage Interest and Property Tax Deduction

I co-own a home with someone (not married) and we each contribute 50% to the mortgage / property taxes.  Our filing status is single.  My question is, must each of us deduct 50% of the mortgage interest and property taxes (since that is what we contribute) OR can one of us deduct more if it would lead to a better tax break (as long as it equals 100% between us).  Thank you in advance.