User Profile History and Statistics

Hi,

We have a requirement of making reports in regards to User Profile Completeness.

Basically, we want to show in a graph per month how many % of employees completed a certain Profile Property (e.g. Ask Me About, About Me, etc..)

My questions now is:

- Does SharePoint store all history of changes? How can I view this history?

- If it does, is it per property?

For example, if I updated my About Me data in May, then updated again in June. I am trying to create the report in July. Can I get the information that I updated About Me data in both May and June (not just June)?

The reason is because we already had statistics dating from Oct 2012 to Feb 2013. However, we noticed that Dec 2012 is missing. And we'd like to figure out if we can still get the statistics for Dec 2012.

Thanks!