Story I - Mysterious Birth Years
The KDD-98 data contained interesting anomalies for date of birth:
- Spikes on years ending in zero
- No individuals were born prior to 1910
- There were twice as many individuals who were born on even years as on odd years
Graph adopted from KDD’99 Competition by Jim Georges and Anne Milley, SAS institute
SIGKDD Explorations, Jan 2000, Volume 1, Issue 2, page 79