Now why might the numbers be increasing?

The Mail reports that:

'Soaring numbers of young children are being diagnosed with special needs, including speech and behaviour problems, new figures show.

Schools and nurseries are registering nearly 20 per cent more under-fives with special needs than two years ago.'

Now why are the numbers so rapidly and massively increasing? Is it because more children are so affected or is it because children so diagnosed qualify for special funding for their school and their parents for extra allowances/credits and of course because there is an industry of therapists and 'experts' who need to justify their salaries.

Yes I know that some children are genuinely affected by disorders such as ADHD but there are even more being diagnosed as such who ate just 'naughty', 'badly behaved' or just plain 'vile'.