In the ten years up to last year, the UK population aged 85 and over has increased by 31%, the Office for National Statistics reported.

The number of women aged 85 and over has increased since mid-2005 by 21%.

The number of people aged 65 and over has increased by 21%.

The population of the UK reached 65.1 million (65,110,000) in mid-2015 – an increase in one year of 513,300 (up 0.8%) – the report stated.

The older population has continued to grow, with over 11.6 million (17.8% of the population) aged 65 and over and 1.5 million (2.3% of the population) aged 85 and over in mid-2015.

This annual rise of the population as a whole - 0.8% - was similar to the average annual increase seen over the last decade, officials said.

The ONS report stated: “The population increase of the UK in the year to mid-2015 included natural growth (more births than deaths) of 171,800 people, net international migration of 335,600 and an increase of 5,800 people in the armed forces and prison populations.

“Natural growth was smaller than in previous years (down 54,400) caused largely by an increase in the number of deaths (up 52,400), combined with the continuing decrease in the number of births (down 1,900).

“An increase in immigration (up 53,700) and a smaller decrease in emigration (down 22,300) have both contributed to the increase in net international migration compared to that seen in the year to mid-2014.”

The analysis also showed that:

• England’s population grew most quickly of the four UK countries over the year, while Wales had the slowest growth
• the population of England increased by 469,700 (up 0.86%) to 54,786,300 and accounts for 84% of the UK’s population
• the population of Scotland increased by 25,400 (up 0.47%) to 5,373,000 and accounts for 8% of the UK’s population
• the population of Wales increased by 7,100 (up 0.23%) to 3,099,100 and accounts for 5% of the UK’s population
the population of Northern Ireland increased by 11,100 (up 0.60%) to 1,851,600 and accounts for 3% of the UK’s population