Hello,
Please check the documentation available in the folder macros-libreoffice included in the package (Advanced and Premium licenses). In this package you can find all information about using getStatistics and other extra options included in the conversion plugin based on LibreOffice. You need to add a macro to your installation of LibreOffice to be able to use getStatistics.
The conversion plugin based on MS Word also includes a getStatistics function (examples/FormatConversion/getStatistics folder).
You can choose the conversion plugin: libreoffice or msword, that best suits your needs to get document statistics.
Regards.