Homeless young rough sleepers in London have doubled in the last four years

According to this article by Rachel Blundy in the London Evening Standard homeless young rough sleepers in London have doubled in the last four years:  http://www.standard.co.uk/news/london/number-of-young-rough-sleepers-in-london-doubles-in-four-years-9579807.html

Ms Blundy writes:  "Almost half of all London's homeless are from the UK, while almost a third come from Central and Eastern European countries. The number of Romanians (730) has replaced Poles (627) as the most frequently seen nationality in the latter group."

If the young rough sleepers have doubled over the last four years, and if half the current number of young rough sleepers are from the UK, is it unreasonable to conclude that the increase in young rough sleepers is entirely made up of immigrants?

That we are importing destitute people from around the world?