Website link：https://flowingdata.com/2022/01/20/declining-births/
The number of monthly births has been falling for the past decade as people marry later and have fewer children. The pandemic initially seemed to speed up the process, but then bounced back quickly, according to provisional data from the CDC. Instead of using absolute monthly counts, the baseline chart uses 2003 as a reference, the earliest monthly data currently available from CDC through its WONDER database. Each point on the line shows the percentage difference between a given month and the corresponding month in 2003.