The profound demographic and economic changes that occurred in Finland after World War II affected the Finnish family. Families became smaller, dropping from an average of 3.6 persons in 1950 to an average of 2.7 by 1975. Family composition did not change much in that quarter of a century, however, and in 1975 the percentage of families that consisted of a man and a woman was 24.4; of a couple and children, 61.9; of a woman with offspring, 11.8; of a man and offspring, 1.9. These percentages are not markedly different from those of 1950. Change was seen in the number of children per family, which fell from an average of 2.24 in 1950 to an average of 1.7 in the mid-1980s, and large families were rare. Only 2 percent of families had four or more children, while 51 percent had one child; 38 percent, two children; and 9 percent, three children. The number of Finns under the age of 18 dropped from 1.5 million in 1960 to 1.2 million in 1980.. How many fewer persons were there on average in a family in 1975 compared to 1950?