periodic table: how do the boiling points of the halogens change from the top to the bottom of the group?

how do the boiling points of the halogens change from the top to the bottom of the group?

Learning the periodic table in chemistry and im not exactly sure what this means? Does it have to do with the fact that the higher the number the more it becomes nonmetalic and the lower you go the less it becomes nonmetallic?

Could you briefly explain it for me? thanks!