then determine what proportion of the total national income is received by
each income group. For example, Table 5.1 shows a hypothetical but fairly
typical distribution of income for a developing country. In this table, 20 individuals, representing the entire population of the country are arranged in order of ascending annual personal income, ranging from the individual with
the lowest income (0.8 units) to the one with the highest (15.0 units). The total or national income of all individuals amounts to 100 units and is the sum of all entries in column 2. In column 3, the population is grouped into quintiles of
four individuals each. The first quintile represents the bottom 20% of the population on the income scale. This group receives only 5% (i.e., a total of 5 money units) of the total national income. The second quintile (individuals5 through 8) receives 9% of the total income. Alternatively, the bottom 40% of the population (quintiles 1 plus 2) is receiving only 14% of the income,
while the top 20% (the fifth quintile) of the population receives 51% of the total income.