For the "Mar 16, 2011" credential that has been replaced, move the text "Credential Replaced: Dec 02, 2011" to beside (perhaps in parans "()") the "Mar 16, 2011" (not sure red is needed)
Perhaps "Mar 16, 2011 - Dec 02, 2011: Credential Replaced"
For extra emphasis, add "Dec 02, 2011 - Present" for all active credentials
Capturing some ideas as I review the interface:
@DJ_Gordon @wadeking98