Transformer Typical X/R

What do you base your transformer typical X/R ratios off of?

The software selects a typical X/R based on the transformer size.
There are some typical X/R in the book "A Practical Guide to Short-Circuit Calculations" by Conrad St. Pierre.
Creation date: 1/6/2017 3:01 PM      Updated: 1/6/2017 3:01 PM