[racket] Typed racket in DrRacket

When I run the simplest possible racket program in DrRacket definitions window

#lang racket
1

the result 1 and the prompt appear instantaneously in the interactions window,
but when I change this to typed racket

#lang typed/racket
1

it takces two seconds before the result 1 and the prompt are displayed
in the interactions window
also
#lang typed/racket
(time 1)

gives the expected result of:
cpu time: 0 real time: 0 gc time: 0

but this still takes two seconds to appear in the interactions window.

Why with a simple program like this does the result take so much
longer for typed racket compared to racket  to be displayed in the
interactions window.

thanks,
Harry Spier