Breast size differences
Breast size in women varies due to genetic and racial variability. There are differences in any group, but useful generalities can be made. I have written about this subject indirectly in previous posts:
World map of breast size
Here is a recent map I came across produced by Target Map. I cannot vouch for the accuracy of the data, but in my professional experience, the findings hold true.
Regions with the largest breast size are in red, regions with the smallest in green.
Women in the Far East and the Indian subcontinent tend to have smaller breasts and stature, while central European women tend to have larger bodies and breasts by nature. Nevertheless, some of the differences are interesting.
Breast implant companies that manufacture saline and silicone breast implants have produced data that shows that the average breast implant size in the US increases the farther south one goes. There is also an increase in average breast implant size as one goes west. Obviously, women in southern and southwestern parts of the US have more occasion to have their breasts in view due to warmer weather than women in Maine, for example, which may contribute to the use of larger breast implant sizes.
What we do not know is the extent to which men in different regions prefer different breast sizes.
Here is a similar map of penile size across the world. We all know men exaggerate in this regard, so take these results with a grain of salt!
Dark green shows largest penile size and dark red the smallest.