Revisions of December birth numbers by year 

2018, 2019 and 2020 figures have been revised up in previous years by around 17,000 births. 2021 figures have not yet been revised, so they remain lower.
Shows births by date of occurrence, before and after updates were applied by the ABS. Figures for 2021 will be revised by the ABS at a later date.
Chart: RMIT FactLab Source: ABS Get the data