Quaternary education or fourth stage education, is the educational level following the completion of an undergraduate degree at a college or university. Graduate and postdoc programs are examples of quaternary education.
... is spread out with 25.2% under the age of 18, 5.7% from 18 to 24, 31.9% from 25 to 44, 23.3% from 45 to 64, and 13.9% who are 65 years of age or older. The median age ...