Powershell for TotalItemSize and UseDatabaseQuotaDefaults

Hi

I need a PS report in 2013 which shows only mailboxes with  TotalItemSize > 4GB and UseDatabaseQuotaDefaults value

I get TotalItemSize from Get-MailboxStatistics

I get UseDatabaseQuotaDefaults from Get-Mailbox

I have tried Get-Mailbox -ResultSize unlimited | where ExchangeVersion -EQ "0.20 (15.0.0.0)" | Get-MailboxStatistics | Where TotalItemSize -GT "4 GB (4,294,967,296 bytes)" | ft Identity,TotalItemSize but this returns no results

This is useful but doesn't quite meet my requirement: https://social.technet.microsoft.com/Forums/en-US/f55b84a7-8aba-4d75-a446-a2007c06daa0/list-of-mailbox-quotas-and-totalitemsize?forum=exchangesvradminlegacyany suggestions?

Thanks

shapi