Demography Ashry Gad Mohamed Prof. of Epidemiology

Science studies population from various aspects: Size Composition Distribution

Population size Number of all persons in the community. Census Estimated population

Census A process of enumeration of all persons in the community. Time: 10 Years Procedures: Enumeration Demographic Socioeconomic

Methods 1- De Jure Counting individuals at their legal residence regardless of their physical presence. Factual Expensive

2-De Facto Counting individuals wherever they actually are one the day of census. Easier Economic

Estimation Methods 1-Natural increase (Number of live births – Number of deaths) added to last census population. No migration in or out.

2-Arthmatic mean Two consecutive censuses Mean annual increase Population = last census +(Mean annual increase X number of years). Example: Annual increase = 10000/10 = (9 X 1000) = 49000

3- Geometric method Most accurate Special equation

Graphical method

Saudi population

Population 26,417,599 note: includes 5,576,076 non-nationals (July 2005 est.)

Age structure 0-14 years: 38.2% (male 5,149,960/female 4,952,138) years: 59.4% (male 8,992,348/female 6,698,633). 65 years and over: 2.4% (male 334,694/female 289,826) (2005 est.)

Median age (2005 est.) total: years Male: years. female: years.

Sex ratio (2005 est.) At birth: 1.05 male / female Under 15 years: 1.04 male /female years: 1.34 male /female 65 years and over: 1.16 male /female Total population: 1.21 male/female

Life expectancy at birth (2005 est.) Total population: years Male: years Female: years

Dependency Ratio Total Dependency Ratio= 60 years / years Young Dependency Ratio = <15 / years. Elderly Dependency Ratio= >60 years / years