Give the ability to report on login counts within a specific date range

As part of driving WorkFront adoption we wanted to be able to have good KPIs to measure. One of the obvious KPIs was just logging into WorkFront. Currently there does not appear to be an easy way to get that without running the same report to get current login counts for each user and then comparing that to last week to get the 'delta'. You should be able to get the login counts within a specific date range.