title: Django admin interface to display aggregates
body: <p>I want to use django admin interface to display aggregates of data in a model. Ex: Model has following fields [employee name, salary, month] I want aggregate table with fields [month, total_salary_paid, cumulative_of_month_salaries_paid]. how do I do this ?? I have searched internet but didn't find any way to do it..any reference or guidance would help</p>