A women's academy - opened in 1997 by what is now City College, Birmingham - has helped to change all that. Last year its A-level results were above the national average. Julie Allder, a former director of the women's academy and now assistant principal for 16 to 19-year-old studies at City College, says it responded to a demand for post-16 courses for women.
Not all of the pupils are under 19 and not all are Muslim. Last year there were 365 at the academy, about half of whom were adults, including white and Afro-Caribbean women.
The women's academy is just one example of the attempt to increase participation by running centres targeted at specific groups of learners. Up to 500 students attend a sixth-form centre at Newtown, one of the more disadvantaged areas of Birmingham. Mary Green, whose job is to widen participation at City College, says the centre attracts young people who are not high achievers and might feel uncomfortable in a traditional sixth-form college. "They like the feeling of being in a sixth-form centre, whereas others prefer the atmosphere in an adult further-eduction college."
Saying-on rates in Birmingham and Solihull, the local Learning and Skills Council area, are about six percentage points down on the national average.
Ms Green says too many courses are aimed at high achievers. "We are trying to fill gaps for disadvantaged people who left school without qualifications."
While co-operation between colleges and schools with sixth forms is better in some areas than others, she says there is an overall desire to raise standards. "It's in our interest for the whole post-16 sector to be good," she adds.
Birmingham and Solihull Local Skills Council has announced a review of the provision for 16 to 19-year-olds, with input from the two local authorities. Participation rates, students' travel patterns and the range of courses on offer are among the issues that will come under the spotlight.
Achievement and participation rates are higher than five years ago. But David Cragg, executive director of the LSC, believes there is still some way to go. He is concerned that 10 per cent of Birmingham school-leavers are unemployed or not seeking work. The rates are even higher in the Afro-Caribbean, and Pakistani and Bangladeshi communities.
"We are not going to do the job of schools and colleges for them, but we can help them set up a more coordinated approach," he says. "We want a shared planning process between ourselves and local providers."