In 1970, Congress instituted a random selection process for the military draft. All 366 possible birth dates were placed in plastic capsules in a rotating drum and were selected one by one. The first date drawn from the drum received draft number one and eligible men born on that date were drafted first. In a truly random lottery there should be no relationship between the date and the draft number. However, this dataset suggests that men born later in the year were more likely to be drafted.
Number of cases: 366
1. Day: Day of month (1-31)
2. Month: Month of year
3. Mo.Number: Month of year (1=January, 2=February, etc.)
4. Day_of_Year: Day of year (1-366)
5. Draft_No.: Draft number assigned to those born on this date
Reference: David S. Moore and George P. McCabe (1989). Introduction to the Practice of Statistics.