Android auto backup - how to know when the last backup was made?

I am using the Android AutoBackup feature in my app. These are my manifest settings.

<application
android:allowBackup="true"
android:fullBackupContent="@xml/backup_rules"
android:fullBackupOnly="true"

Is there a way to know when the last backup for my app was made?

from Android auto backup - how to know when the last backup was made?