It all depends what you use as scale. There is the 8 ft/unit school and the 8.6 ft/unit.

Poser measurement tools use 8.6 ft/unit. Many content makers use however 8 ft/unit, leading to exaggerated figures.

As to what is most common the wisdom of the market may be the best advisor. What clothing size does your local shop sell most of?

Anyway there are considerable variations around the globe