Why in the world has this day been so crazy? My teacher left the zoom meeting leaving me as the host. I have so much school work to do. (Do you want to help?) How has your day been? StarSwirlDreamGirl

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.