Download Counter plugin is the easiest way to display a download link and counter for your users, on Joomla!
This free plugin is ideal if you want to provide your visitors with a very straightforward download option. In fact, all they'll need to do is click a link to get the needed file. It is more effective and improves the user experience the simpler it is. You have the option to show the quantity of downloads for your files and to limit download access to specific users based on their user group. You can read the documentation here.