Table 3. Spanish, British and Irish comparative surname analysis.

	Spain	Britain	Ireland
Total N	1766	1654	953
No. surnames analysed	37	38	21
No. clusters found	79	80	41
Avg. cluster size	10.1	12.6	16.1
% men in clusters	45.1	59.2	67.7
Avg. cluster age	536	545	829

Proportion of men in clusters and average age of descent clusters.