Starting in the 1880s, birth rates began to drop steadily in the industrialized countries, as women married later and families in urban living conditions increasingly favoured having fewer children. This trend was particularly acute in the United Kingdom, where birth rates declined from almost 35.5 births per 1,000 in the 1870s to about 29 per 1,000 by 1900. While the cause is uncertain, the 29% decline within a generation shows that the birth control methods Victorian women used were effective.