The British Agricultural Revolution, or Second Agricultural Revolution, was an unprecedented increase in agricultural production in Britain arising from increases in labour and land productivity between the mid-17th and late 19th centuries. Agricultural output grew faster than the population over the century to 1770, and thereafter productivity remained among the highest in the world. This increase in the food supply contributed to the rapid growth of population in England and Wales, from 5.5 million in 1700 to over 9 million by 1801, though domestic production gave way increasingly to food imports in the nineteenth century as the population more than tripled to over 35 million. The rise in productivity accelerated the decline of the agricultural share of the labour force, adding to the urban workforce on which industrialization depended: the Agricultural Revolution has therefore been cited as a cause of the Industrial Revolution.