The decrease in the percentage of slum dwellers is mostly due to a change in the definition of adequate sanitation. In 2005, only a proportion of households using pit latrines were considered slum households, whereas in 1990 and 2001 all households using
Number of sleeping rooms was not collected in some DHS surveys. Countries with other data sets with information on number of sleeping rooms, Simulation method was used to estimate the proportion of households with sufficient leaving areas. .
Direct estimation from 2005 DHS data. However simulation was used to compute sufficient living for 2005.