Hi roks.
Firstly most of our flights are not augmented. We do more and more so called "Ultra long Haul" flights, but they are still a minority of our flights. At present we have (if I count correctly!!) eight destinations that require a four pilot crew (with two more starting this year) and four or five that require three pilots.
On trip requiring four pilots, most involve being the "Operating" crew in one direction, in which case you art credited with all the flight, and "Augment" in the other, in which you are credited with hours actually in the seat (so approximatley half)