Custom Drupal Analytics with Views- how to track the number of users by role over time? I am building a social networking website in Drupal.  As users complete their profile, they are awarded different roles.  Now that I have launched the site and have some members, I would like to track the number of users by role over time so that I can see how my site is growing.

I built a view to do this and it shows me the information I want.  However, since I want to measure membership growth I would like to do this over time.  So, currently I simply log into my site and then type the numbers I need into Excel.

Is there a better way to do this?  Ideally, I would like to automatically save an Excel-ready snapshot every week (or in a dream world, have a graph automatically prepared).  Is there some other way (even without views) to track the number of users by role over time?
You should record custom variables in Google Analytics. Download the GA Module https://www.drupal.org/project/google_analytics and Tokens
https://www.drupal.org/project/token
in the bottom of the configuration [yoursite].com/admin/config/system/googleanalytics 
expand the SHOWCUSTOM DIMENSIONS section
populate the values with tokens like [current-user:roles]
You can also record an event upon account creation which identifies the type of account
https://developers.google.com/analytics/devguides/collection/analyticsjs/events
you can do a JS event on submit that will record or it probably makes more sense to create a library to record all instances of certain types the way Google Developers is implying.