Autosegmental phonology is a modification of generative phonology[?] introduced by John Goldsmith in his PhD thesis in 1976. He introduced the notion of parallel tiers of segments and called this autosegments a name which is a bit misleading. As an application example he presented a detailed phonological analysis of the Igbo language[?] spoken in Nigeria.
... 45 to 64, and 9.4% who are 65 years of age or older. The median age is 42 years. For every 100 females there are 126.2 males. For every 100 females age 18 and over, ...