Hello Sophia,
Thank you for your question regarding Awstats. Each domain is listed separately on the Awstats page in cPanel. Anyone who has cPanel access can see any of the domains listed. If you have multiple customers on the same cPanel, you may not wish to give those customers full access to cPanel since they would also have access to other user's site files.
You may want to look into using something like Google Analytics for each site. That way, each website would have a separate Google Analytics account and each of your customers could log into their own Google Analytics account to view their website statistics.
Please let us know if you have any additional questions or need further assistance.
Regards,
Christi N.