Growth of Archive Manager users over 10 years ?

I have been asked to show for the business the current growth of archive manager for the last 10 years - would it be possible to gather the growth of users of Archive Manager for over the last 10 years and how might this be done ?
  • we don't have data available in Archive Manager, where we would see time and date when the user was added from AD into Archive Manager. Looking into the Archive manager SQL database, the only time stamp we have available here is date and time of the last scan of a users mailbox - I don't see any possibility here to gather historic data of a user / mailbox over that period of time