The Sibley-Munroe checklist was a landmark document in the study of birds. It drew on extensive DNA-DNA hybridisation studies to reassess the relationships between modern birds.
... the town the population is spread out with 22.3% under the age of 18, 6.7% from 18 to 24, 28.0% from 25 to 44, 25.8% from 45 to 64, and 17.2% who are 65 years of age ...