1. Demography Ashry Gad Mohamed Prof. of Epidemiology

2. Science studies population from various aspects: Size Composition Distribution

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

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

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

6. 2-De Facto Counting individuals wherever they actually are one the day of census. Easier Economic

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

8. 2-Arthmatic mean Two consecutive censuses Mean annual increase Population = last census +(Mean annual increase X number of years). Example: 1400 30000 1410 40000 Annual increase = 10000/10 =1000 1419 40000 + (9 X 1000) = 49000

9. 3- Geometric method Most accurate Special equation

10. Graphical method

11. Saudi population

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

14. Age structure 0-14 years: 38.2% (male 5,149,960/female 4,952,138). 15-64 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.)

15. Median age (2005 est.) total: 21.28 years Male: 22.84 years. female: 19.28 years.

16. Sex ratio (2005 est.) At birth: 1.05 male / female Under 15 years: 1.04 male /female 15-64 years: 1.34 male /female 65 years and over: 1.16 male /female Total population: 1.21 male/female

17. Life expectancy at birth (2005 est.) Total population: 75.46 years Male: 73.46 years Female: 77.55 years

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