Birth, Fertility Rates At a New Low in U.S.
Natl Center for Health Statistics repts US birth and fertility rates in '73 dropped to their lowest points in history; natl fertility rate dropped to 1.9 children per family, below 'replacement level' of 2.1 children; if current trend continues, US will reach stage of zero population growth sometime in 1st half of 21st century; birth rate for '73 was 15 births for every 1,000 persons, 4% lower than '72 rate, which was also a record low; rate of population increase was 5.6% compared with 6.2% for '72; chart showing total fertility rate for '45-'73 (M)