Arbuthnot's data describes male and female births for London from 1629-1710.

John Arbuthnot (1710) used these time series data to carry out the first known significance test. During every one of the 81 years, there were more male christenings (births) than female christenings. As Arbuthnot wondered, we might also wonder if this could be due to chance, or whether it meant the birth ratio was not actually 1:1.

Data Source: HistData package in R.

• year: The year, ranging from 1629 to 1710.
• boys: Number of male christenings (births).
• girls: Number of female christenings (births).