There are now three routes connecting the domestic airport and the CBD - ending up at the Esplanade Bus Terminal.
#37 travels via the Belmont Forum shopping centre
#36 and #40 via Great Eastern Highway (the motel strip)
#36 in the other direction finishes at the Midland train station.
Weekdays
First trip from PER to the CBD is 05:32 (#36)
Last trip 00:15 (#40)
There is an attempt to space the departure times.
Happy wandering
Fred