Library Statistics

This ticket is part of a larger issue to implement KPIs that measure certain aspects of the library.

The KPIs

The library would like to aggregate the following metrics for loans

• average waiting time
• average loan duration
• average count of new loans
• (and more)

Hereby, they want to group the loans on certain parameters like

• creation date of loan
• state of the document while the loan was requested
• (and more)