England and Wales population has jumped by 3.7 million over the last decade, the biggest growth in numbers in any period between censuses since the headcount began 210 years ago in 1801, as per new figures.

The number of people living in England and Wales is 56.1 million, a rise of 7% on the 52.4 million registered in the 2001 census. Migration, increased life expectancy and rise in fertility rates are responsible for the unprecedented hike, claimed the Office for National Statistics (ONS).

ONS elaborated, around 55% of the growth in population, or 2.1 million, between 2001 and 2011 was the result of net migration, and 45%, or 1.6 million, was the result of increased life expectancy and fertility rates.

The figures also showed an unprecedented number of ageing people, over-65s. One in six people is now in this age group in England and Wales. There are 900,000 over-65 and 430,000 over-90 people.

Also, there are over 400,000 more under-fives compared with 2001. ONS concluded, it reflects a rise in the number of women of child-bearing age because of inward migration.

London, where the population increase is the largest, grew by 12%, gaining more than 850,000 inhabitants and taking its total population to more than eight million. The local authority with the fastest growing population was Tower Hamlets in east London registering a 26.1% population rise in the last decade, followed by the east London authority of Newham at 23.5%. Manchester is the third biggest population growth by local authority at 19% since 2001.

The figures are from the first wave of data released since the 2011 Census held on March 27 last year, which is the biggest so far.