Analysis of the year in which the first cohabitation not ending in marriage began provides an indicator of the level of change over time in the proportion of people who have had a cohabiting union which did not end in marriage. Reported cohabitations show an increase over time, and although no age standardisation has been carried out, the size of the variation means this represents a real increase in the proportion cohabiting in each decade.

• Among men currently aged 16 to 59 2% reported starting such a cohabitation in the 1960s. In the 1970s this figure was 12% compared to 37% in the 1980s and 47% in the 1990s.
• The equivalent figures for women were 1%, 10%, 41% and 47%.

Women were more likely than men to start their first completed cohabitation at a younger age, 38% had started their first cohabiting union by the age of 19 compared with 19% of men. The age at which people started their first completed cohabitation also varied with the year in which the cohabitation began. For both men and women, those starting their first cohabitation between 1990 and 2001 tended to start at an older age than those who started their first completed cohabitation in the 1960-70s. For cohabitations started in the 1960-70s 45% of women started a first cohabiting union by the age of 19 compared with 34% between 1990 and 2001; the equivalent figures for men were 25% and 16%.