In fact, most areas outside Cardiff and its surroundings had more people in that age group leave than move there.

It is something that has concerned not just people in those areas - but also MPs in Westminster.

A Commons committee recently set up an inquiry to look at population change in Wales and why many younger people seem to be moving elsewhere.

The 2021 census shows the population of Wales grew by 1.4% in the last 10 years, the lowest growth of any UK nation.

The Welsh Affairs Committee says it is "especially keen to understand why younger people appear to be leaving Wales" as part of its investigation.

With the findings of the inquiry expected in due course, Sky News has spoken to some young people from Wales to find out what made them leave.

'Challenge myself'

Eurgain Wyn is 25 years old and originally from Pembrokeshire in West Wales.

She studied at the University of Bath before moving to London two years ago.

Eurgain says there is an expectation that younger people should stay in Wales.

"I wanted to challenge myself so I decided to go to Bath," she said.

"I think a lot of people in Bath, their plan is: you finish studying and everyone moves to London, so I never considered anything else. I always wanted to move to London."

For Eurgain, living in London is about expanding her horizons and seeing more of what the world has to offer.

"That's not something you can do if you stay in Wales," she said.

"Being in your 20s is a pivotal time. People want to explore and do anything they can in that decade."

Her brother has also left Wales and is currently living in Qatar.

"He's been there for six years with no sign of coming back anytime soon," she added.

"When you have these opportunities, you shouldn't hold back and stay with what you're comfortable with."

Read more:
45% of 16 to 25-year-olds fear they won't earn enough to start family
Higher interest rates could be good news for young people

'Lack of work'

Sion Owen, 23, is originally from Anglesey but moved to Manchester last May.

He said a lack of jobs in his line of work meant he had to look further afield.

"The reason I moved was the lack of work in Anglesey, Bangor and North Wales for what I wanted to do, more on the business side," he said.

"What I've been hoping for is support after coming out of university or college.

"The only work I see around here is for joiners, traders, engineers, nurses.

"There are so many businesses down in the south [of Wales] and if they want to expand their business, they should have offices up in the north too."

According to Sion, higher salaries the other side of the border were also attractive.

"The thing about the city, and England, is there's more money to be earned in England than there is at home. That's the most unfortunate thing about it," he added.

"I'm only a couple of hours away from home but there are a lot more jobs available here."

'Bit of a change'

Kieran Hughes is originally from Newport in South Wales.

The 24-year-old has been living in London for two years.

After completing his studies at Cardiff University, the pandemic was a "major contribution" behind Kieran's move.

"For me, it was just wanting a bit of a change, to leave South Wales for a tiny bit and see what else is out there and secondly, employment opportunities," he said.

"I work in the legal industry, so there were more employment opportunities for the line of work I wanted to do on a commercial and corporate law side within London, as opposed to say Cardiff or Newport."

For Kieran, the "buzz" of a city like London is also attractive.

"There are more things going on outside of work," he said.

"For someone like myself who enjoys things like music gigs, it just feels like whenever someone does a big UK tour they always miss Cardiff or anywhere in South Wales. So especially going out in London there are more opportunities to see artists and comedians."

Kieran believes things could "definitely" be done to retain more younger people in Wales.

"I think it's just more attractive employment opportunities back in South Wales, or back in Wales in general," he said.

"It's hard to shy away from the fact salaries are a bit higher elsewhere - there'll always be a pull to different locations across the UK when there are more attractive employment packages going on."

Read more Wales news:
Automatically registering voters will 'remove barriers'
House from hit Netflix series Sex Education up for sale

'Make a difference'

The subject of young people leaving Wales, and rural areas in particular, was recently debated in the Senedd.

The Welsh government's economy minister, Vaughan Gething, said he wanted people to see "the positivity of staying in Wales".

"My ambition is a simple one. I want to see more jobs and better jobs across Wales," he said.

"I want opportunities for businesses to start up and to grow."

Mr Gething said he did not want young people to see it as "a point of national service that you must come back [to Wales] regardless of opportunities".

"I want to be positive and optimistic about the things we can do, even in the times we'll face in the year ahead and more, we will still have opportunities to make a difference," he added.

"I want people to see that in a range of areas, you can make choices and have a really good life that is economically successful in a country that is not just small, but is brilliant."

'Young person's game'

But will the young people who spoke to Sky News return to Wales?

Eurgain says she will stay in London for now but would like to return home in the future.

"If I were to have children I would want them to have a Welsh education, and a similar upbringing to what I had, so obviously I would then move back to Wales," she said.

"Perhaps not straight back to Pembrokeshire, for example, maybe to Cardiff, but not in the near future."

Sion, too, hopes to be able to find work in Anglesey in the future.

"That's the goal, but at the moment there aren't enough jobs available," he said.

While some of Kieran's friends who also live in London have "no intention of coming back" to Wales, he does not see the London life as being "forever" for him.

"I do see myself coming back to South Wales," he said.

"Being a London boy feels like a young person's game. It's not forever. I'm from South Wales, my family are here, friends I've grown up with are here, and the cost of living here is a lot kinder than elsewhere."

The Welsh government released a statement in response to the comments.

A spokesperson said: "We are doing everything we can to help young people to plan their futures in Wales. Using the distinctive strengths of local economies, we are working to create better jobs and increase skills to support businesses against an increasingly difficult economic backdrop.

"We are tackling the issue of large numbers of second homes, which can affect communities and their sustainability, by implementing the broadest package on interventions seen in the UK. A record level of investment has also been made to support our commitment to deliver 20,000 additional homes for rent in the social sector this government term."