How to retrieve the size of the Recovery Services Backup Storage Vault in Azure Powershell?

I am currently working on an Azure Powershell Script that retrieves the names of the Recovery Service Vaults, the protected VMs, as well as the current size of the vault.

However, I am unable to retrieve from Powershell the current size of the vault that stores the backups, which is available on the Azure portal 

Get-AzureRmRecoveryServicesBackupProperty only gives the BackupStorageRedundancy Property, but not the size. Neither the vault data (Get-AzureRmRecoveryServicesVault), the storage context (Get-AzureRmRecoveryServicesVaultContext), the backup container (Get-AzureRmRecoveryBackupContainer), nor the backup item (Get-AzureRmRecoveryBackupItem) seems to have the size property I need.

Is this option implemented in Azure Powershell yet? If yes, which cmdlet gives me access to this data? If not, when will this be implemented?