Further details of the calculations and the full set of values calculated can be found in the Annex. In such a case, the median income of the distribution is easily identifiable and the number of individuals subsisting on less than a certain proportion of the median (e.g. 40%, 50%, or 60%) is simple to count directly. However, given the wide variety and uneven coverage of household survey data, a number of tools allow poverty measures to be estimated directly from more aggregated data sources, such as grouped distributional data that can be derived from either household surveys or administrative sources.