Gauge search info: Add last used to ID gauges that have not been used in X months.

We have over 30 pages of gauges and 10 people across the organization that are creating gauges (Leadership, Directors, Managers). I can guarantee that there are duplicated gauges and gauges that were created years ago that haven't been used. 

I know I can filter by unused as well as last updated but that doesn't give the full picture. It could have been last modified and last used a week ago. 

I want to be able to filter based off last maintained AND last used (on a Dashboard/Report/Goal) was 6+ months ago. Having a last used field that would be updated daily would be beneficial.