Enterprise Vault data report and category ?

Hi People,

How can I find and generate the data report as follows:

1. How long we can go back / retrieve from the EV (what's the oldest data that is stored in EV) ?
2. How can I show / categorize data size by year to determine the purge policy to free up disk space ?
 

I cannot find it in the EV console.

Any idea and suggestion even in the SQL script would be greatly appreciated.

Thanks !