I think you need the joint name statements even if you are married (which I am). On the document checklist, there is a section for 'Genuine relationship evidence' which starts off with 'If you are married or in a de facto relationship, evidence of a genuine and continuing relationship with your partner to the exclusion of all others....Evidence can include, but is not limited to, joint bank account statements, billing accounts in joint names, and other evidence of cohabitation.'
I guess if you have the statements however old they are, upload them!