How are you getting that piece of information into the system in the first place? You could create a versionable attribute on the CI which stores an owner value. Every time the value changes, a new version of the CI is created. You would need to determine what type of versioning you would like to use. This will only work from the point in time you implement it going forward.
I'm guessing you allocate a CI to a user via the admin tool and want to track those changes? With 7.4 you can do the linkage/relinkage in a process so I'd suggest a small Move CI process which does the admin bit for you in the process, but as a side effect also tracks that such a change has been done.