(o) For historical times (e.g. the last 165 years): How fast did reproduction rates regress toward the mean?
* a parent of such a family has about five times as much children as the average German (~1.4) and about 3.5 times as much children as the average German parent; Although it is said that the average German woman has 1.4 children, women of German descent have less children (~1.1, Birg). Childlessness occurs frequently. For that reason the average German family has 2 children (and not just one).