How old were the actors in Labyrinth (1986)?

Frustrated with babysitting on yet another weekend night, Sarah, a teenager with an active imagination, summons the Goblins to take her baby stepbrother away. When little Toby actually disappears, Sarah must follow him into a fantastical world to rescue him from the Goblin King. Guarding his castle is the labyrinth itself, a twisted maze of deception, populated with outrageous characters and unknown dangers.