Private schools account for a growing proportion of pupils in secondary education in England, statistics show.
Population trends mean there are fewer poorer teenagers
Over the past five years the number of pupils in the independent sector has not risen, but they are a greater proportion of the 11-15 age group.
There were 232,730 pupils in 2004, 7.1% of the age group. This year there are 232,620 but they make up 7.3%.
There were about 5,000 fewer aged five to 10 in prep schools, the proportion being more constant: 5.5% to 5.6%.
There were dramatic differences between individual local authorities.
In the London borough of Kensington and Chelsea, 44.2% of those aged 11 to 15 are attending private schools. In Cornwall it is just 4%.
The overall figures have led some of those in the independent sector to suggest that more parents are opting to go private.
Last month Schools Minister Lord Adonis said he wanted of wanting to tap the "educational DNA" of independent schools to transform weak state schools.
He appealed to the independent sector to run state-funded academies.
The president of the independent Girls' Schools Association, Pat Langham, said such an attitude was bound to influence parents' choices of schooling.
"When you have a government which is seeking what has been called the 'DNA' of the independent sector, you can't blame parents for actively seeking that for their child as well," she said.
But the answer lies mainly in demographic shifts.
The government is keen to get more young people from working class families to consider higher education.
In 2005-06, £386m was spent on widening participation, improving retention rates and helping disabled students.
Population estimates highlighted by the Higher Education Policy Institute suggest the number of young people available to go into higher education will decline sharply in the next decade.
And the fall will be mainly in the social groups least likely to go to university.
The government has always said it is confident that its policies mean the proportion of students from poorer backgrounds will increase.
UK universities took a slightly higher proportion of students from state schools last year, the Higher Education Funding Council for England said.
The rate was 87.4% of young undergraduates in 2005-06, up from 86.7% the year before.
Schools Minister Jim Knight said: "We are interested in the many, not just the few."
He added: "The overwhelming majority of parents are clearly satisfied with the state education system - new research from Keele University shows that nine out of 10 are happy with their children’s schools.
"The state school system is continuing to deliver for parents, regardless of their wealth or background, with record results across the board - but we are committed to driving standards up even further."
The general secretary of the National Association of Head Teachers, Mick Brookes, said: "We have to consider what it is that parents are buying when they opt to go to the independent sector.
"Apart from the name of the school, they are buying smaller class sizes and
quite often enhanced resources."
And he said: "Some parents are buying the fact that their children are not going to be quite as pressured by the tables, targets and tests regime that we have in the state sector.
"I've spoken to parents who say 'I don't want my child to grow up like this, I
want my child to grow up enjoying education'.
"That is becoming more difficult in the current regime in state schools."