Bridget Jones Britain: Married couples MINORITY as number of singles soars Around 17.8m Britons - a third of the population - say they are single Number of divorcees up by a fifth in a decade to 4.5m people There are around 113,000 civil partnerships in Britain, 2011 census shows Many couples choose to co-habit or marry later in life, experts say Immigrants now form 13% of population - from 4.9m in 2011 to 8m in 2011 By Ellie Buchdahl Britain is becoming of singletons, partners and co-habiters, as the number of people choosing not to marry has rocketed by 3.6million in just a decade, according to new figures. The final results from the 2011 census from across the UK show that more than a third of the population - around 17.8million people - now class themselves as single. This means the number of British singletons has increased by a quarter - while the number of divorcees has risen by a fifth to 4.5million people. Bridget Jones generation: Renee Zellweger played Helen Fielding's famous singleton in the film version of the eponymous diarist's life story Same-sex civil partnerships, which did not even exist a decade earlier, accounted for around 113,000 people in 2011 census. The figures also show that - thanks, experts say, to mass immigration and a baby boom - the proportion of people old enough to marry who have chosen to do so has fallen from 51 per cent to below 47 per cent. Many couples now choose to co-habit rather than tie the knot in the traditional way. But the figures also betray the phenomenon of the 'Bridget Jones generation' - named after the single heroine of Helen Fielding's novel series, and describing men and women of marriage age who remain unmarried. Yet despite the decrease in traditional mother-and-father couples, the number of family cars on British roads is increasing twice as fast as the human population. Meanwhile, the number of widows fell by more than 300,000 as men catch up with women in terms of life expectancy. There are also one million more pensioners than there were a decade ago and 600,000 more full time unpaid carers, while one in six Britons is over 65. Immigration has also soared - spurred by the expansion of the EU - and foreign-born residents now account for 13 per cent of the UK's population. Some 8million foreign-born people now live in the UK - a 4.1 million increase on the 4.9million of 2001, which has boosted the British population to 63.2 million. The number of Polish-born people living in the UK has increased tenfold in a decade. Four in ten Londoners are from an ethnic minority - although in Northern Ireland non-white people account for only two per cent. The wedding: Colin Firth and Renee Zellweger play Mark and Bridget when they did eventually get hitched... although Helen Fielding's latest novel sends Bridget back to singledom And it gives a glimpse of lifestyles have changed even more than the population. Despite the impact of environmentalism and a renaissance in cycling, the number of family cars on British roads are increasing twice as fast as the human population. Yet, in a vivid illustration of the impact of the impact of improvements in medical care, the number of widows in Britain fell by more than 300,000 - in evidence that men are finally closing the gap on women in life expectancy. Harry Benson of the Marriage Foundation think-tank said that it was undeniable that marriage was losing its popularity - but stressed that it is still widely seen as the desirable way to bring up children. 'It's misleading to look at the population as a whole - the majority of families with children - five eighths of couples with children - are married,' he said. But what is a worrying is the way the trend away from marriage reflects the rise of family breakdown. Although the number of divorces has gone down, over the last ten years, the rise in family breakdown is due to a very simple equation - the rise in family breakdown is due to the decline in marriage.