The average age of mature students is increasing, according to latest analysis by the Higher Education Statistics Agency.
Based on work used to inform a government-sponsored research project, the analysis shows that the profile of mature students has shifted in terms of both age and gender.
Mature student numbers increased overall by 2.7 per cent between 1994-95 and 1997-98, after rising in 1995-96 and slumping again in the following two years.
But the movement varied dramatically according to age group.
While the number of mature undergraduate entrants aged between 21 and 23 fell by more than 20 per cent, the number among the over-50s rose by 77 per cent.
Excluded from these figures is the Open University, which shows the opposite trend.
At the OU, it was the younger age groups that increased - by more than 50 per cent at ages 21 and 22 - while numbers among the over-40s and 50s fell.
Also striking is the 12.5 per cent fall in the number of mature male students, compared with a 16 per cent increase in the number of mature females, although both male and female student numbers have fallen among those studying for first degrees.
The highest growth subject area was humanities, with a 216.6 per cent increase over four years in numbers of part-time mature students, followed by agriculture and related subjects. In contrast, numbers studying mathematical sciences dropped by more than 40 per cent and more than 22 per cent in business and administrative studies.
Denise Bamford, who carried out the analysis for Hesa, said that the recent decrease in mature student numbers partly reflected the fact that more people in their 20s would have been able to enter higher education as school leavers.
But she said that qualitative research was needed to explain the full picture.