The UK's youngest and oldest populations by city have been revealed - with Sheffield featuring among them.
The new figures have revealed the UK's youngest and oldest populations, city by city.
Britain is getting older, as in the last two decades the average age has risen by two years to 40.
And Sheffield ranks as one of the places with a younger population with the average of someone in the town at 38.9 years old.
Defining a city as an urban area where more than 135,000 people live, academics at the Centre for Cities have worked out where the youngest and oldest cities in the UK are.
Slough is the youngest city in the UK with an average age of just 33.9 years old and only one in 10 people aged 65 and over.
A spokesman said Slough has a young population because it has one of the highest birth rates of all UK cities - 16.6 for every 1,000 residents, compared to the British average of 11.8.
Blackpool has the oldest population of any UK city, with an average age of 43.2.
Here's how local cities were ranked: