Complete Data Series
The complete data series includes the following types of data:
- Live birth counts
- Death counts
- Population size on January 1st
- Population exposed to risk of death (period & cohort)
- Death rates (period & cohort)
- Life tables (period & cohort)
Period data are indexed by calendar year, whereas cohort data
(if available) are indexed by year of birth.
Cohort Death Rates (and Exposure)
are provided if there are at least 30 consecutive calendar
years of data for that cohort. For example, the mortality series
for Sweden begins in 1751, therefore we can show death rates for
the 1675 birth cohort for ages 76 and older. The cohort death
rates at younger ages are shown as missing (denoted by ".").
Similarly, if the mortality series ends in 2002,
we can show death rates for the 1972 cohort up to age 29 because by
December 31, 2002 everyone in that cohort has reached age 30.
Yet, mortality data for age 30 will remain incomplete until December
Cohort Life Tables
are presented for a population if there is at least one cohort observed
from birth until extinction (i.e., the date by which all cohort members
are assumed to have died). In that case, life tables are provided for all
extinct cohorts and for some almost-extinct cohorts as well (see the
Methods Protocol, pp. 42-44).
Format of Data Files
- Data files are tab-delimited text (ASCII) files.
- Files are organized by sex, age, and time.
- Population size is given for one-year1 and
five-year2 age groups.3
- Deaths,3 exposure-to-risk, death rates, and
life tables are given in similar formats of age and time:
- 1x1 (by age1 and year)
- 1x5 (by age1 and 5-year time interval)
- 1x10 (by age1 and 10-year time interval)
- 5x1 (by 5-year2 age group and year)
- 5x5 (by 5-year2 age group and 5-year time interval)
- 5x10 (by 5-year2 age group and 10-year time interval)
- Deaths are also given by Lexis triangles (i.e., by age,1
birth cohort, and calendar year).3
1One-year age groups (or "by age") means 0, 1, 2,..., 109, 110+.
2Five-year age groups means 0, 1-4, 5-9, 10-14,..., 105-109, 110+.
Age groups are defined in terms of completed age, so "5-9"
extends from exact age 5 to just before the 10th birthday (sometimes
written elsewhere as "5-10").
3Some of these numbers are estimates (of population
size or numbers of deaths), not actual counts, and therefore may be
expressed as non-integers.
Life Tables include the following columns:
| Year or range of years (for both period & cohort
|Age group for n-year interval from exact age x
to just before exact age x+n, where n=1,
4, 5, or ∞ (open age interval)
|Central death rate between ages x and
|Probability of death between ages x and
|Average length of survival between ages x and
x+n for persons dying in the interval
| Number of survivors at exact age x,
assuming l(0) = 100,000
|Number of deaths between ages x and
|Number of person-years lived between ages x
|Number of person-years remaining after exact age x
|Life expectancy at exact age x (in years)
Methods Protocol (pp. 34-44) for more details about life table calculations.
- Deaths, population estimates, death rates, and life tables
are provided by single years of age up to 109, with an open age interval
for 110+. However, these data are sometimes the product of aggregate raw
data (e.g., 5-year age groups, open age intervals), which have been
split into single years of age using the methods described in the
Methods Protocol. The original raw data that were extracted from
published or unpublished sources are available from the HMD Input Database.
- For populations with territorial changes, two sets of
population estimates are given for years in which a territorial change
occurred. The first set of estimates (identified as year "19xx-") refers
to the population just before the territorial change,
whereas the second set (identified as year "19xx+") refers
to the population just after the change. For example,
in France, the data for "1914-" cover the previous
territory (i.e., as of December 31, 1913), whereas the data
for "1914+" reflect the territorial boundaries as of January 1, 1914.
- For period life tables, the central death rate m(x) is used
to compute probabilities of death q(x). The values of m(x) below age
80 are by definition equal to the observed population death rate M(x)
shown on each country page. At older ages, however, the number of
deaths and the exposure-to-risk eventually become quite small, and
thus observed death rates display considerable random variation. Therefore,
we smooth the M(x) values for ages 80 and older and use these smoothed
values to compute q(x) above a certain age (based on the number of
observed deaths). For details, see the
Methods Protocol (pp. 35-37). This procedure helps to avoid certain
difficulties in period life table calculations at older ages that
may be caused by: 1) extremely high death rates resulting from exposure
being smaller than the number of deaths, 2) death rates of zero resulting
from no deaths at an age where exposure is non-zero, and 3) undefined
death rates at all ages where exposure is zero. For cohort life table
calculations, such difficulties are not present.
The Input Database houses the raw data that are the basis
for all HMD calculations. Input data files for each population
are accessible from the country page.
Every country/area has at least three input data files:
births, deaths, and population size. For countries that have experienced
border changes during the period covered by the HMD, the Input Data
also include a file of territorial adjustment factors.
In addition, there are four PDF files for each population.
The Background and Documentation file contains basic information
regarding the data for that particular population. The Notes
file contains specific notes pertaining to individual data points.
The Data sources and Reference files include a complete list of data sources
for every number in the raw data files, with the latter file also containing codes that
link these sources to individual data points in these files.
Format of Data Files
- Data files are stored in comma-delimited text (ASCII) files.
Structure of the Input Database for detailed information about
data types and file formatting.
- The Input Data are manipulated according to procedures specified by the
Methods Protocol to create the
Complete Data Series.
- An important goal of the HMD is to provide users with open access to
all the Input Data. However, we must limit access in a small number of
cases because of restrictions imposed by the organizations or individuals
who have contributed the data.