There are a couple of new apps on WikiTree that provide some interesting statistics on your family tree. The first is Ancestor Statistics – if you’re a WikiTree member, go here and log in to see your stats. Here are mine:
I have identified all of my 3rd great-grandparents and have their profiles on WikiTree. After that, it drops off significantly. I only have 45% of my 4th great-grandparents, 32% of my 5th great-grandparents; 22% of my 6th great-grandparents and 15% of my 7th great-grandparents.
The average generation length in my family tree is 30 years. Curious about how that compares to others, I did some google searching and found this article on the International Society of Genetic Genealogy (ISOGG) wiki that highlights some studies that show generations to be around 25 to 30 years for females and 30 to 35 years for males. So my 30 year average generation length seems about normal.