How do I report & adjust the 1099-DIV, 1099-INT and 1099-B for joint brokerage accounts with 50% ownership interest?

I have a joint brokerage account with a non-spouse. We each have 50% ownership interest in the brokerage account and file separate tax returns. The 1099's have my social security number. I would not consider either of us "nominees" as the funds belong to us jointly. I do not see an obvious means to designate these as joint accounts nor adjust the amounts on a percentage basis. It is not clear whether each field should be adjusted individually nor whether each field should be reduced by the same 50% ownership amount. For example, If there is $1k in total dividend, $400 in qualified dividends, and $10 in foreign taxes paid - do each decrease by 50%?