If you look at ZIP's Acquisition of QuadPay presentation
TTV HY20
July 14.9
Aug 23.4
Sep 32.7
Oct 49.1
Nov 96.1
Dec 100.2
= 316.1m
In the report they use $273.5m
Seems to be by multiplying through at 0.6659 for US dollar then dividing by 0.77 (current rate) to get back to AUD.
If you use $316.1m (rather than constant currency) growth for Zip US is 207% and much closer to that of APT like for like.