Exchange Mailbox Analyzer

Hello Guys,
Can you please tell me if EMA scans mailbox DB and public folders DB in Exchange 2013 SP1?
I've ran the analyzer, but it gave me a 350Gb DB which is totally different from 800Gb reported by the exchange. From those 800Gb, the customer told me that about 200Gb are public folders.
Anyway, even with 200Gb summed with our 350Gb that is not the total of 800Gb reported.
What can this be? White Space?
Thank you.
Kind regards,
NS