Austin has an action figure collection of 500 action figures. He keeps 435 of the action figures on his wall. What percentage of Austin's action figure collection does he keep on his wall?

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.