Population: Total population and distribution by age and sex estimated to be consistent with the population by age and sex of the (a) 1956, 1966, 1976, 1986, 1991, 1996, 2006, 2011, 2016 censuses; (b) adjusted for under/over count; (c) adjusted for age heaping; (d) adjusted for under enumeration of children under age 15; and with estimates of the subsequent trends in fertility, mortality and international migration.  In addition, the (a) 1959 Survey and 1973-1976 PGS and 1994 MFS survey estimates; (b) official estimates through 2023 have been considered.

Fertility: Total fertility rate and age pattern of fertility based on: (a) registered births classified by age of mother and the underlying female population by age through 2021; (b) births in the household in the preceding 12 (or 24) months classified by age of mother from the 1966, 1976, 1991, 1996, 2016 censuses and 1973-1976 PGS and 1988, 1993 PS and 1996 PES and 2002 SCIH; (c) indirect estimates obtained from the application of the reverse survival method to the 1956, 1966, 1976, 1991 censuses and 1973-1976 PGS; (d) indirect estimates obtained from the application of the own-children method of fertility estimation to the 1986, 1996, 2006, 2011, 2016 censuses and 2010 MIDHS; (e) cohort-completed fertility backdated by the mean age of childbearing from the 1986, 2006, 2011 censuses and 2002 SCIH.  In addition, the (a) official estimates of age-specific fertility rates through 2016; (b) birth-histories data from the 1996 MFS; (c) indirect estimates obtained from the application of the reverse survival method to the 1956-2010 Education Stats and 1986, 1996, 2006, 2011, 2016 censuses have been considered.

Child Mortality: Under-five mortality based on: (a) official estimates of infant and child mortality through 2017; (b) registered infant and child deaths through 2021; (c) direct estimates from births and deaths under-five calculated from full birth histories data from the 1973-1976 PGS and 1989 KAP and 2000 IDHS and 2010 MIDHS; (d) indirect estimates from data on children ever born and surviving from the 1986, 1996, 2006, 2011 censuses and 1991 BS and 1996 PES and 1998 PGS; (e) recent household deaths from the 1956-2017 Estimates and 1984, 1994 MFS and 1997-1999 GHS; (f) International estimates used up to 2021.  In addition, the (a) indirect estimates from data on children ever born and surviving from the 1977 FS and 1987, 1992-1995, 2002 SCIH and 1990 MPC and 1994 MFS and 2016 Census; (b) recent household deaths from the 1998 PGS have been considered.

Overall Mortality: Life expectancy at birth and age pattern of mortality based on: (a) official estimates through 2007; (b) registered deaths by age and sex available through 2021; (c) adjusted for underreporting of infant and child deaths; (d) adult deaths adjusted for underregistration using death distribution methods; (e) mortality rates for older ages were adjusted; (f) estimates using CD West model life tables and estimates of infant and under-five mortality (5q0), and adult mortality (45q15).

Adult and Old Age Mortality: Estimates derived from: (a) deaths by age and sex available from Register through 2020; (b) adjusted for underregistration; (c) recent household deaths data by age and sex from the 1956-2007 Estimates and 1973 VIS and 1973-1976, 1998 PGS and 1977 FS and 1984, 1994, 1996 MFS and 1986, 1991, 1996 censuses and 1987, 1992-1995 SCIH and 1990 MPC and 1991-1994 IPS and 2000 IDHS; (d) intercensal survivorship from successive census age distributions; (e) estimates of under-five, adult and old age mortality.

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.