Typically 18-20". Few go to 20-22". Occasionally slightly under 18".
Billy Chow is 182.5 cm.
Vivian Chow is 5' 6".
China Chow is 5' 2".
Jeremy Chow is 5' 9".
Jessica Chow is 5' 3".
Maximillian Chow is 6' 3".
Micki Chow is 183 cm.
Niki Chow is 174 cm.
Vic Chow is 180 cm.
Valerie Chow is 5' 8".
Kam Pong Chow is 5' 6".
She is 5'7