The designations employed and the presentation of material throughout this publication do not imply the expression of any opinion whatsoever on the part of UNESCO, the OECD and IDB concerning the status, name, or sovereignty over any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.Nomenclature is given according to the organization that is the source of the corresponding graph in this joint UNESO-OECD-IDB publication.