Several sources are used to obtain the coverage of birth and death registration for more than 230 countries and areas. The primary source is the "Quality of vital statistics obtained from civil registration" page on the United Nations Demographic Yearbook Vital Statistics Questionnaire. Source of information also includes United Nations Statistics Division workshops that have been conducted in the past, when covearge information was obtained from country representative(s) either from the National Statistical Office or the Civil Registration Authority attending the workshop. When information is not available from these two sources, coverage information estimated by the International Institute for Vital Registration and Statistics (IIVRS), UNICEF (Multiple Indicators Cluster Survey), ICF Macro (Demographic and Health Survey) and/or the World Health Organisation is then used.