WASHINGTON (AP)—Ninety-five percent of state prison inmates in 1986 were repeat offenders or were serving time for violent crimes, the government reported Sunday.

Among the other 5 percent, about half were convicted drug traffickers or burglars, concluded the study by the Justice Department’s Bureau of Justice Statistics.

The data, based on a survey of 13,700 inmates, showed the percentage of violent and repeat offenders among a nationwide state prison population of 450,000 to have remained about the same as the figures for 1979, the last time such a study was conducted.

“Despite a period of rapid growth in the size of the inmate population, its composition has remained stable,” concluded the study by Christopher Innes of the Bureau of Justice Statistics. State prison population in 1979 was under 300,000.

The survey did find that the state prison population has gotten somewhat older, less educated and increasingly Hispanic. The median age increased from 26 in 1979 to 28 in 1986, while education among prisoners fell by a year, from 11 to 10.

Hispanics were 12.6 percent of the prison population in 1986, compared with 9.9 percent in 1979. The percentage of white prisoners, about 50 percent, and blacks, 47 percent, remained about the same from 1979 to 1986.

The survey found that four out of five of state inmates had previously been imprisoned or placed on probation.

Two-thirds of the inmates were serving time for a violent crime or had previously been convicted of one.

About 53 percent of all inmates were repeat offenders who also had a record of at least one violent conviction.

Of the 5.3 percent of the inmates who were first-time offenders and serving time for non-violent crimes in 1986, 25 percent had been convicted of burglary and 26 percent for drug trafficking.

More than 60 percent of the state inmates had two previous convictions, 45 percent had three and nearly 20 percent had six or more prior terms of probation or prison.

Half the inmates said they were under the influence of drugs or alcohol when they committed their crimes.

There was an increase from 1979 to 1986 in the percentage of inmates who used drugs during or shortly before the time of the offense.

Thirty-five percent of the inmates in 1986 said they were under the influence of drugs at the time of the offense, compared with 32 percent in 1979. Forty-three percent of the inmates said they used drugs daily in the month before the offense, up from 40 percent in 1979.