Who Are The Unfollowers In My Twitter Audience?

Unfollowers are those user profiles who stop following you after they had followed you previously. You can view the list of your Unfollowers by selecting the option of 'New Unfollowers' under the Tracking criterion in the left column in the Audience section.  

This will list down all the latest user profiles who have unfollowed you. You may follow/unfollow these profiles by clicking on the corresponding button shown in the user profile card.