Users page > sort by last login field

I'm looking for way to monitor the activity on my OC instance, especially while on-boarding a crop of new users.
Specifically, I'm trying to see which users have logged in recently. The user page has the 'last login' column, but
this table is not sortable. Since users are authenticating through an LDAP server with thousands of users, most
having 'never' logged in, I currently have no way of knowing which users have logged in, except by looking
at the log file. The activity page does not record log in events.

Can anyone suggest a way to track user logins?