WASHINGTON — Americans were victimized by an estimated 34.1 million crimes last year, a decline of three-quarters of a million from 1985 and down more than 7 million from the peak year of 1981, the government reported Sunday.
The survey of about 100,000 people in 50,000 households by the Bureau of Justice Statistics found that the rate of violent crime dropped 6.3% last year contrasted with 1985 and has fallen 20% since 1981.
The survey, which does not include homicides, counts crimes whether or not they were reported to police and uses the results to estimate the number of criminal incidents nationwide.
Criminologists say the five-year downward trend is caused by the aging of the baby-boom generation, the movement of people born after World War II out of the age group, from 15 to 24, most prone to commit crimes.
As the children of baby boomers come of age in increasing numbers later this decade, crime levels should begin turning upward because of the "sheer number of children entering their teen-age years," said Marvin E. Wolfgang, professor of criminology and law at the University of Pennsylvania, Philadelphia.
Last year's figures may represent a bottoming out of the decline, which showed some signs of slowing down in 1986, said Alfred Blumstein, dean of the school of urban and public affairs at Carnegie-Mellon University, Pittsburgh, Pa.
In the first three years of the decline, which began in 1981, the number of crimes fell by nearly 6 million.
The number of assaults per 1,000 people fell 7.9% last year, and there were smaller declines in the rates of rape, theft, burglary and household larceny, the survey found.
Motor vehicle theft rates rose 5.4% in 1986, apparently reflecting the increasing tendency of organized crime to get involved in stealing autos. Robbery rates, meanwhile, went up 1.4%.
Since 1981, the rates of rape, robbery and household burglary have fallen more than 30%, and personal theft and household larceny rates have dropped more than 20%.