Complex sentence: There are no precise dates for when this cohort starts or ends; demographers and researchers typically use starting birth years ranging from the early to mid- 1960s and ending birth years ranging from the late 1970s to early 1980s.
Split into simpler sentences: There are no precise dates for when this cohort starts or ends. Demographers and researchers typically use starting birth years ranging from the early to mid- 1960s and ending birth years ranging from the late 1970s to early 1980s.