Population: Total population and distribution by age and sex estimated to be consistent with the population by age and sex of the (a) 1975, 1988, 2003 censuses; (b) adjusted for under/over count; (c) adjusted for age heaping; (d) adjusted for under enumeration of children under age 15; (e) 1994-1995 DHS and 2000, 2019 MICS survey estimates; (f) official estimates through 2006; and with estimates of the subsequent trends in fertility, mortality and international migration.  In addition, the (a) adjusted for under/over count; (b) adjusted for age heaping; (c) adjusted for under enumeration of children under age 15; (d) only total population for 1965 Census have been considered.

Fertility: Total fertility rate and age pattern of fertility based on: (a) birth-histories data from the 1994-1995 DHS and 2019 MICS; (b) births in the household in the preceding 12 (or 24) months classified by age of mother from the 1959-1960 Survey and 2000, 2010 MICS; (c) adjusted fertility using Brass P/F ratio method (or variants) with data on children ever born and births in the preceding 12 (or 24/36) months, both classified by age of mother, from the 1975, 1988 censuses; (d) indirect estimates obtained from the application of the reverse survival method to the 1975, 1988, 2003 censuses and 2006, 2010 MICS; (e) cohort-completed fertility backdated by the mean age of childbearing from the 1959-1960 Survey and 1975 Census and 1994-1995 DHS and 2006, 2010, 2019 MICS.  In addition, the (a) births in the household in the preceding 12 (or 24) months classified by age of mother from the 2003 Census and 2006 MICS; (b) adjusted fertility using Brass P/F ratio method (or variants) with data on children ever born and births in the preceding 12 (or 24/36) months, both classified by age of mother, from the 2003 Census; (c) indirect estimates obtained from the application of the reverse survival method to the 1956-2009 Education Stats and 2000 MICS; (d) cohort-completed fertility backdated by the mean age of childbearing from the 1988 Census and 2000 MICS have been considered.

Child Mortality: Under-five mortality based on: (a) registered infant and child deaths through 1960; (b) direct estimates from births and deaths under-five calculated from full birth histories data from the 1994-1995 DHS; (c) indirect estimates from data on children ever born and surviving from the 1975, 1988 censuses and 2000, 2006, 2010 MICS; (d) International estimates used up to 2021.  In addition, the (a) direct estimates from births and deaths under-five calculated from full birth histories data from the 2019 MICS; (b) recent household deaths from the 1959-1960 Survey and 1988, 2003 censuses and 2012 ENSNM have been considered.

Overall Mortality: Life expectancy at birth and age pattern of mortality based on: (a) The demographic impact of AIDS has been factored into the mortality estimates; (b) estimates using HIV/AIDS model life tables and estimates of under-five mortality (5q0) and adult mortality (45q15) with UNAIDS estimates of adult HIV prevalence, and ART coverage for children and adults.

Adult and Old Age Mortality: Estimates derived from: (a) recent household deaths adjusted at adult ages for underregistration using death distribution methods; (b) maternal orphanhood from the 1988 Census and 1994-1995 DHS and 2000, 2006 MICS; (c) paternal orphanhood from the 1988 Census and 1994-1995 DHS and 2000, 2006 MICS; (d) estimates of under-five, adult and old age mortality.  In addition, the (a) recent household deaths data by age and sex from the 1959-1960 Survey and 1988, 2003 censuses; (b) siblings deaths from the 1994-1995 DHS have been considered.

Migration: International migration based on: (a) information on foreign-born populations from censuses and registers from major countries of destination; (b) estimates derived as the differences between overall population growth and natural increase; (c) UNHCR statistics on the number of refugees in the main countries of asylum.