Each year, the Foundation for Child Development (FCD) and the Child and Youth Well-Being Index Project at Duke University issue a comprehensive measure of how children are faring in the United States. The resultant National Child and Youth Well-Being Index (CWI) is based on a composite of "28 Key Indicators of Well-Being," grouped into "seven Quality-of-Life/Well-Being Domains." These Domains are: Family Economic Well-Being, Safe/Risky Behavior, Social Relationships, Emotional/Spiritual Well-Being, Community Engagement, Educational Attainment, and Health. This year's report highlights: Long-term trends in the CWI, in its seven Domains, and in its 28 Key Indicators, 1975-2012. Specifically, this year's report includes: (1) Calculated values of the CWI for each of the years from 1975, the base year of the Index, to 2010; (2) An updated estimate of the CWI for 2011 based on observed values of Key Indicators that have become available since last year's report; (3) An initial estimate of the CWI for 2012 based on those observed values of the Key Indicators for 2012 that are currently available, along with projections of the other Key Indicators; and (4) A review of long-term trends in the seven Domains and 28 Key Indicators of the CWI, highlighting each Domain and Indicator's beginning value in 1975 (or the earliest year for which data are available); ending values in 2012; and high and low values with the corresponding years in which these occurred. [For the report from the previous year "National Child and Youth Well-Being Index (CWI), 2012," see ED542868.]