The variations of sex ratio by districts in Sri Lanka

Abstract

Sex ratio is one of the most important population ratios for demographic studies and it can be used to describe the degree of balance between two elements, male and female, of the population. Sex ratio is the number of males available for 100 females and it considered as one of the key social indicators. There are three types of Sex ratios: primary, secondary and tertiary. The primary sex ratio means the ratio which is measured at the time of conception. The secondary sex ratio refers to the ratio that is measured at the time of birth. Tertiary sex ratio denotes the ratio of mature organisms.