List OWA enabled users and mailboxes size

I would like to export all users who enabled OWA and the total mailboxes size. I can use two command to export the data to csv.

Get-CASMailbox | Select DisplayName, OWAEnabled | Export-CSV D:\OWA.csv

Get-MailboxStatistics -database "Database1" | Select DisplayName, TotalItemSize | Export-CSV D:\Size.csv

But, how to get the OWA enabled user and mailboxes size into one csv?

Thank you very much!