Women are main breadwinners in 40% of the U.S.families

Women are the main or even the only breadwinners in 40% of the American families with children under 18 y.o., confirms the survey conducted by Pew Research Center (PRC) on the basis of data presented by the U.S. Bureau of Census. To compare, in 1960 women kept only 11% of families.
As PRC puts it, 63% of these women are a single parent (8.6 million) in the family. 37% (5.1 million) of them are married, and earn more than their husbands. At the same time during the last 50 years the share of women, whose income exceeds the earnings of their husbands, increased from 4% in 1960 to 11% in 2011.
Meanwhile the revenues of two groups differ much. Thus, the income of single parent families in 2011 amounted to $23,000 on the average in the USA., and the income of families where women earn more than husbands is about $80,000.
To compare, the same indicator for all American families with children for 2011 was at the level of 57,000.
Now women comprise 47% of all labour force in the USA. The share of working women with children in 1960 was 37% and in 2011 the reading grew to 65%.