Weighted averages for a region, taking into account the relative size of the relevant population of each country. The figures for countries with larger populations thus have a proportionately greater influence on the regional aggregates. The averages are derived from published data complemented by imputed values for missing countries. Imputations are based on publishable data for the same countries from previous and/ or following years. When imputing an indicator, information from related indicators is used to strengthen the imputation hypothesis.