Wales and the North East of England have the lowest university application rates in the UK, Ucas data demonstrate.
Figures published on 23 July show that less than 31 per cent of 18-year-olds applied to higher education from those regions in 2013, compared with rates of 48 per cent in Northern Ireland and 42 per cent in London.
According to Demand for Full-time Undergraduate Higher Education, in all regions the application rate has risen since 2004.
The biggest jump is in the North West of England, where the proportion has increased by 38 per cent.
Some of the changes since 2004 have reduced or reversed regional differences, Ucas adds.
In 2004, 18-year-olds in the South East were nearly 20 per cent more likely to apply to university than those living in the North West; in 2013, this difference had reduced to 4 per cent.
Source: Demand for Full-time Undergraduate Higher Education, Ucas
Notes: Map designed so that the size of each area approximates the size of its population. Demand for higher education in further education colleges in Scotland is not included.