The table below counts the number of direct lineal ancestors about whom some information is known (the count is inaccurate for the remotest medieval generations, where not all lines have been entered into the GEDCOM file from which this count was generated, and no ancestors beyond the 21st generation, which includes Edward III and Philippa of Hainault, have been entered).
The following are the meanings of the terms in the chart ("Diff" and "Unique" are only given when different from "Found"):
Gen Total Found Diff. Unique Percentage 0 1 1 100.00 % 1 2 2 100.00 % 2 4 4 100.00 % 3 8 8 100.00 % 4 16 16 100.00 % 5 32 30 93.75 % 6 64 44 42 68.75 % 7 128 60 56 46.87 % 8 256 90 82 35.15 % 9 512 124 112 24.21 % 10 1024 149 139 135 14.55 % 11 2048 172 166 152 8.39 % 12 4096 119 113 99 2.90 % 13 8192 49 47 42 0.59 % 14 16384 25 25 24 0.15 % 15 32768 15 0.04 % 16 65536 10 0.01 % 17 131072 6 0.00 % 18 262144 9 0.00 % 19 524288 10 0.00 % 20 1048576 11 0.00 % 21 2097152 5 0.00 % All 959 871