If you are using Site Administrator for SharePoint (try the trial here), and you want to track document versioning and duplications, then follow these steps.
1. The document and versioning information can be found at different levels within Site Administrator's Information Portal. You can scroll down the Enterprise report to the Top 5 largest documents, then click View more:
2. Similarly, you have the Documents link from farms, web applications, sites, etc. – so you can drill down from any level you want.
3. The report you get no matter which level you are at will look something like this. Note the report does not show all documents, so go ahead and download the CSV to view the ful report.
4. Once I get the raw data in Excel, I can make a quick pivot table: