The bar chart compares the changes in percentage of Australia women in six distinct age brackets when giving first childbirth at 20-year intervals. Overall, all age groups experienced upward trends with an exception of both 20-24 and 19 and younger age ranges, which showed declines over the surveyed time frame.
Regarding escalating age groups, women falling into the 25-29 age bracket climbed from around 39% in 1966 to a peak of approximately 51% over the 20 years later, after which it receded to roughly 41% by the end of the period. Meanwhile, both female individuals falling in the 35-39 and 35-39 cohorts recorded significant increases in giving birth to their first child, starting at about 11% and 9% to roughly 49% and 29%, respectively. Women aged 40 or more, despite a slight rise of approximately 4% in the figure, remained the least proportion of giving first childbirth.
Concerning the remaining age ranges, in 1966, the leading age group went to women in the 20-24s, with figure for just above 60%, after which it dropped by roughly 50% in the final year, securing in the third position with 30%, and reflecting the postponement of motherhood over the three periods. Finally, women who had their first child in the last age group falling from around 35% in 1966 to just above 10% by the end of the period.