United States yearbook - 1982 (1)

5 8 Vital Statistics
Fertility and life expectancy.—The total fertility rate, defined as the number of births that 1,000
women would have in their lifetime if, at each year of age, they experienced the birth rates occurring
in the specified year, is compiled and published by NCHS. Other data relating to social and
medical factors which affect fertility rates, such as contraceptive use and birth expectations, are
collected and made available by both NCHS and the Bureau of the Census. NCHS figures are
based on information in birth and fetal death certificates and on the 1973 and 1976 National Surveys
of Family Growth; Bureau of the Census data are based on decennial censuses and the CPS.
Data on life expectancy, the average remaining lifetime in years for persons who attain a given
age, are computed and published by NCHS. For details, see the technical appendix in V ital S ta tistics
o f the U nited States.
Marriage and divorce.—The compilation of nationwide statistics on marriages and divorces in
the United States began in 1887-1888 when the National Office of Vital Statistics prepared estimates
for the years 1867-1886. Although periodic updates took place after 1888, marriage and
divorce statistics were not collected and published annually until 1944 by that Office. In 1957 and
1958, respectively, the same Office established marriage- and divorce-registration areas. Beginning
in 1957, the marriage-registration area comprised 30 States, plus Alaska, Hawaii, Puerto Rico, and
the Virgin Islands; by 1979 it Included 42 States and the District of Columbia. The divorce-registration
area, starting in 1958 with 14 States, Alaska, Hawaii, and the Virgin Islands, included by 1979 a
total of 30 States and the Virgin Islands. Procedures for estimating the number of marriages and
divorces in the registration States are discussed in VitaI Statistics of the United States, voi. I l l -
Marriage and Divorce. Total counts of events for registration and nonregistration States are gathered
by collecting already summarized data on marriages and divorces reported by State oifices of
vital statistics and by county offices of registration.
Another important source of data on marriage and divorce trends in the United States Is the
March supplement to the Current Population Survey conducted monthly by the Bureau of the
Census. For further details, see text, p. 2.
Vital statistics rates.— Except as noted, vital statistics rates computed by NCHS are based on
decennial census population figures as of April 1 for 1940, 1950, 1960, and 1970; and on midyear
population figures for other years, as estimated by the Bureau of the Census (see text, p. 2).
Race.— Data by race for births, deaths, marriages, and divorces from NCHS are based on information
contained in the certificates of registration. In NCHS’s National Survey of Family Growth
and the Census Bureau’s Current Population Survey, race is determined by interviewer observation.
Statistical reliability.—For discussion of slatistical collection, estimation, and sampling procedures,
and measures of statistical reliability applicable to Census Bureau and NCHS data, see Appendix
III.
Historical statistics.—Tabular headnotes provide cross-references, where applicable, to H is to rica
l S tatistics o f the U nited States, Colonial Times to 1970. See Appendix I.
Figure 2.1
Legal Abortions — Number and Rate per 1,000 Women
15-44 Years Old: 1974 to 1980
"■ Millions ; Rate per 1,000 women
2.0 --------- — -------------------------------- : ------------------ :------ — ------------ 40
NUMBER OF ABORTIONS
ABORTION RATE
Source: Chart prepared by U.S. Bureau o f the Census. For data, see table 104.