To calculate the notification incidence of tuberculosis in different areas within the
suburbs, the enumerator sub-district (ESO) boundaries used for the 1991 population census were superimposed on the property boundary coverage and the incidence for each ESO calculated after tabulating the number of people with tuberculosis in 1991 in each ESO and expressing the
number as a ratio to the 1991 population for each ESO as recorded by the census