GA retirement exclusion needs to allocate income between taxpayer & spouse. Taxable joint accounts report my SSN. Is 100% me for exclusion or 50-50 because joint account?

In the Georgia retirement exclusion exclusion section it says, we need to allocate some income between taxpayer and spouse. We have a taxable joint account. The brokerages say that they report capital gains and dividends on my SSN. Is the account considered mine for the Georgia exclusion purposes  is it split 50-50 because it's a joint account?