Mozy has some reporting tools that may be of help to you. Here is a link with general information about our reporting tool.
Here is a link to our documentation about our graphs and reports which has more detailed information about our graphs and reports which may be enough information about the backups data usage that you're looking for.
Did you find the information that Jared provided useful? If what you want exactly isn't something offered there in the reporting, please take a moment to leave a feature enhancement request in our Idea Exchange so we can get the developers looking into options for further reporting.