Exporting exchange user info

Hello,

I'm currently running Exchange 2010. I have a script that I run every so often to get mailbox sizes for all users:

Get-Mailboxserver | Get-MailboxStatistics | Sort-Object TotalItemSize -Descending | Select DisplayName, ItemCount, @{expression={$_.TotalItemSize.value.ToGB()}} | Export-CSV ExchangeReport.csv

My problem is I would like to include the title in this. Is there a way I can add that into this single command? I tried but it's not exporting anything for it. I assume I need to use a different cmlet for the title but Ideally I would like this to be on a single script.

Thanks