Britain is set for a record number of centenarians as 12,050 World War One baby boomers turn 99 and hope to hit three figures next year

Britain is set for a record number of centenarians next year, with more than 12,000 World War One baby boomers on course to hit the milestone age in 2021.

It comes as figures show the UK's elderly population has reached a record high and the number of adults aged 100 rose by more than 10% in the space of a year.

Experts have credited improvements in healthcare and the post-war baby boom in 1919 as the reason behind the increase. 

There were 13,330 centenarians, people aged 100 and over, in 2019 - a 5.2% rise from 2018, the Office for National Statistics estimates.

More than a third of those were new centenarians, an 11% rise from 4,660 in 2018. 

And another 12,025 baby boomers have turned 99 this year, and are on course to hit 100 next year. 

The boom is down to the big increase in births in the second half of 1919, about nine months after the end of the First World War in November 1918. 

Figures show the number of 90-year-olds in Britain has reached a record-high and country

Meanwhile, the number of people over 105, known as semi-supercentenarians, has also risen. 

The number of males aged 105-plus has more than doubled in the last decade, while the number of females of this age has risen by around half.

The figures also show there were 605,181 people aged 90 and over in 2019, a 3.6% rise on the previous year and the highest level on record. 

Just over twice as many women as men were alive at this age last year.

There was a 62% rise in the number of 99-year-olds alive in 2019 compared with the previous year - a result of a birth spike after the First World War. 

Estimates of the very old are calculated from death registration data and occur at the mid-point of each year.

The analysis covers a period before the coronavirus outbreak.

Analysts say they expect the number of centenarians to rise sharply, as a result of the post-war baby boom, but that Covid-19 may influence this.

Rose Giddings, from the ONS's Centre for Ageing and Demography, said: 'The UK population aged 90 years and over grew to its largest size in 2019.

'Historical improvements to male life expectancy continued to narrow the gap between men and women in this age group to its lowest level on record, with around two women to every man.

There were 13,330 centenarians, people aged 100 and over, in 2019 - a 5.2% rise from 2018

The figures also show gap between male and female life expectancy narrowing and the sex ratio for ages 90 years and over between 1987 and 2019 has decreased dramatically 

'Despite a low number of births 100 years earlier, we saw an uptick in the number of people aged 100 years and over in 2019, due to medical advances and improvements in public health during their lifetime.

'The birth spike after World War One has resulted in an unusually large birth cohort who are aged 99 in our latest figures.'

The ONS said improvements in male life expectancy are largely responsible for the growing population aged 90 and over.

While women have historically had longer life expectancies, the gap is narrowing as male life expectancy has increased at a faster rate over many decades.

Separate statistics released by the ONS showed an 11-year gap between the areas with the lowest and highest life expectancies in the UK.

The area with the lowest figure at birth was Glasgow City, at 73.6 years for men and 78.5 for women.

There was a 11.3-year gap between Glasgow City and the highest male life expectancy (84.9 in Westminster) and an 8.7-year gap for women.

In England, there was a 10.5-year gap between the highest life expectancy at birth for men and the lowest (74.4 years in Blackpool).

For women, the gap was 7.7 years between Westminster (87.2) and Blackpool (79.5).

Londoners had the highest life expectancy in England between 2017 and 2019, while those in the North East had the lowest.

Life expectancy in London was 80.91 years for men and 84.69 for women, compared with 78.02 for men and 81.82 for women in the North East.

Experts have credited the baby boom after the First World War for the rise in those aged 99

London has also experienced the largest gain in life expectancy for males (4.9) and females (3.9) since 2000-03.

This compares with 3.3 and 2.4 years respectively for men and women in the North East.

Overall life expectancy in England for men was 79.8 years and for women was 83.4 years, a rise of 2.8 months from 2014-16 for both.

The North West, London, the South East and the South West also saw significant rises for both sexes from 2014-16.

The four most southerly regions - London, South East, East of England and South West - had higher life expectancy at birth estimates than the England average, with London continuing to show the largest gain.

All other regions observed lower life expectancy at birth estimates than the England average.

The West Midlands had the largest life expectancy gap between men and women, with a difference of 46.1 months.