The line graph illustrates the percentage of people in four age groups (18-24, 25-34, 35-44 and 45 and over) between 1990 and 2010.
Overall, the 25-34 age group experienced the most pronounced increase and recorded the highest figure for much of the period. By contrast, the over-45s consistently accounted for the smallest proportion until the latter years, when their figure rose considerably.
In 1990, approximately 13% of those aged 18-24 belonged to the relevant group, compared with around 7% of 25-34-year-olds. The proportion of the former fluctuated slightly before climbing to about 20% in 1998. Having remained relatively stable until 2000, it subsequently rose to just over 30% in 2003 and then levelled off, finishing at roughly 31%. Meanwhile, the 25-34 cohort witnessed a sharp upswing in the late 1990s, reaching approximately 27% in 1998. After a period of modest growth, its figure surged to a peak of around 51% in 2005, before declining and recovering slightly to end at about 47%.
The two older cohorts initially registered comparatively low figures. The 35-44 group increased gradually, whereas the over-45s remained at a negligible level for much of the first decade. Towards the end, however, both groups recorded an upward trajectory, with the over-45s experiencing a particularly substantial rise.