Welsh surnames (thing)

I looked some figures up on this a year or two for a school project. These figures are from a study totalling names from the 6 Wales telephone directories.

Here are the most common 40 surnames:

1. Jones - 60.57 per thousand
2. Williams - 37.81 per thousand
3. Davies - 36.76 per thousand
4. Evans - 24.66 per thousand
5. Thomas - 22.97 per thousand
6. Roberts - 17.14 per thousand
7. Hughes - 13.38 per thousand
8. Lewis - 12.96 per thousand
9. Morgan - 11.7 per thousand
10. Griffiths - 10.9 per thousand
11. Edwards - 10.33 per thousand
12. Owen - 8.85 per thousand
13. James - 7.66 per thousand
14. Morris - 7.5 per thousand
15. Price - 7.5 per thousand
16. Rees - 7.3 per thousand
17. Phillips - 6.34 per thousand
18. Jenkins - 6.23 per thousand
19. Harris - 5.79 per thousand
20. Lloyd - 5.64 per thousand
21. Richards - 5.51 per thousand
22. Powell - 4.72 per thousand
23. Parry - 4.49 per thousand
24. John - 3.65 per thousand
25. Watkins - 3.39 per thousand
26. Howells - 3.25 per thousand
27. Pritchard - 3.14 per thousand
28. Rogers - 2.71 per thousand
29. Matthews - 2.37 per thousand
30. Rowlands - 2.35 per thousand
31. Humphreys - 2.22 per thousand
32. Pugh - 2.19 per thousand
33. Ellis - 2.17 per thousand
34. Bowen - 2.17 per thousand
35. Hopkins - 2.14 per thousand
36. Martin - 1.91 per thousand
37. Bennett - 1.86 per thousand
38. Bevan - 1.69 per thousand
39. Pearse - 1.65 per thousand
40. Adams - 1.61 per thousand

These top 40 surnames only cover 38% of the welsh population, but this could easily be explained by varying numbers of people per telephone, studies taken from different eras, et cetera.