1911 Census of England and Wales, General Report with Appendices, Table 130: " Proportions per 1,000 persons at each Age-Group speaking English only, 1911; and proportion at all ages, 1901 and 1911: in Administrative Counties and County Boroughs".

COUNTIES AND COUNTY BOROUGHS. AGES. TOTAL,
3 years and
upwards.
3-5. 5-10. 10-15. 15-25. 25-45. 45-65. 65
and
upwards.
1911. 1901.
Wales and Monmouthshire 590 590 570 571 542 457 386 1537 498
                 
Monmouthshire (including County
    Borough)
862 893 898 898 862 793 740 863 867
  Monmouth Administrative County 849 880 884 886 841 753 697 842 841
  Newport County Borough 917 947 953 944 937 933 903 939 958
Glamorganshire (including County
    Boroughs)
638 641 626 614 581 509 470 589 559
  Glamorgan Administrative County 579 575 549 536 503 409 371 512 448
  Cardiff County Borough 870 898 904 908 889 853 806 885 908
  Merthyr Tydfil County Borough 591 578 542 505 463 358 309 481 425
  Swansea County Borough 755 761 746 709 685 604 542 689 668
Anglesey 86 77 96 86 100 76 49 85 80
Brecknockshire 630 642 637 633 580 457 385 570 540
Cardiganshire 83 68 53 119 105 78 49 87 67
Carmarthenshire 156 129 112 154 149 108 83 134 95
Carnarvonshire 116 100 89 124 145 124 101 122 103
Denbighshire 478 465 441 430 423 361 323 417 380
Flintshire 616 623 617 590 549 473 412 554 508
Merionethshire 65 57 46 79 99 80 62 77 62
Montgomeryshire 612 608 587 581 534 477 431 540 524
Pembrokeshire 655 687 684 699 652 611 542 653 655
Radnorshire 906 961 965 958 930 917 876 934 937