In addition, we chose data sources in which multiple countries were represented; however, data from the same source may not be available for all countries or for the same year across countries, so caution is needed in making comparisons. For each indicator a primary data source was chosen. When data for a particular country were not available from that source, other sources were used to supplement. When data are available from the same source for multiple years, we note changes in indicators that are five percentage points or larger.