1921 Census of England and Wales, General Report with Appendices, Table 85 : " Wales and Monmouthshire - Proportional Numbers speaking English only, Welsh only, and both English and Welsh, 1891-1921".

Language spoken. Per 1,000 aged
2 years and
upwards.		 Per 1,000 aged 3 years and upwards.
1891. 1901. 1911. 1921.
English only 450 498 537 589
Welsh only 301 151 85 63
Both English and Welsh 239 348 350 308
Other Languages and no statement 10 3 28 40