The graph below shows the changes in UK birth rate of women in 6 different age groups from 1973 to 2008

The line graph illustrates the UK fertility rate of women altered in six distinct age groups over the course of 35 years, starting from 1973.
Overall, the birth rate of women aged 25-29 was the highest figure over a 35-year period. In addition, the number of women from 30 to 39 years old experienced an upward trend, while the other women's age groups saw a reverse tendency.
In 1973, there were about 140 women who fall into the 25–29 age group, and this figure was followed by some fluctuations until it had reached around 120 by the year of 2008. By contrast, the birth rate of 30-to-35-year-old British women went up gradually from over 70 in 1973 to less than 85 in 2008. Similarly, the birth percentage of women aged 35 to 39 remained constant at over 40 by 1988, and then rose significantly to about 62 in 2008.
By contrast, women between 20 and 25, and under 20, gave birth to fewer children over a period of 35 years, going from approximately 125 and 60 births per 1000 residents to roughly 95 and 40, respectively. Likewise, the figure was the lowest for the birth rate of females aged over 40, at 20, and then fell nearly a half in 2008.