Pascale Breuil-Genier, unité des Études démographiques et sociales, Insee
The number of households in France reached 27.5 million in 2009, up 3.2 million on 1999. Most of the increase came from one- and two-person households, up 1.7 million and 1.5 million respectively. The share of one-person households rose in all regions except French Guiana and Corsica. Its growth was strongest in the French West Indies (Martinique and Guadeloupe) and Réunion Island, as well as in north-east mainland France. Its growth was weaker in the Paris region, which had the largest proportion of people living alone in 1999. The increase in one-person households is due to changing patterns of live-in partnerships and population ageing. In a parallel development, the percentage of large families is declining. The statistical data from population censuses allows a description of these trends at highly detailed geographic levels.