Statistics from 1940 show about 100 murders per year in Harlem, "but rape is very rare". By 1950, many whites had left Harlem and by 1960, much of the black middle class had departed. At the same time, control of organized crime shifted from Italian syndicates to local black, Puerto Rican, and Cuban groups that were somewhat less formally organized. At the time of the 1964 riots, the drug addiction rate in Harlem was ten times higher than the New York City average, and twelve times higher than the United States as a whole. Of the 30,000 drug addicts then estimated to live in New York City, 15,000 to 20,000 lived in Harlem. Property crime was pervasive, and the murder rate was six times higher than New York's average. Half of the children in Harlem grew up with one parent, or none, and lack of supervision contributed to juvenile delinquency; between 1953 and 1962, the crime rate among young people increased throughout New York City, but was consistently 50% higher in Harlem than in New York City as a whole.