(CNN) Ohio is the only state ranked "high" for its rate of sexual victimization in juvenile correctional facilities, according to a Department of Justice report released this week that evaluated data from 2018.

However, the report highlighted the difficulty of obtaining sufficient facility data — only about a third of the 327 facilities surveyed in the study had enough youth interviews to be ranked in the report. The report defined sexual victimization as any forced or coerced sexual acts between young people held in juvenile correctional facilities, or any sexual contact between them and facility staff.

More than 15 percent — or about one in six — of the 140 surveyed youth held in Ohio juvenile correctional facilities reported being forced or coerced into sexual activity with other youths or detention staff in 2018, compared to 7.1 percent nationally.

That means Ohio was the only state given a "high" rating of sexual victimization in its juvenile correctional facilities.

Six facilities in Ohio were surveyed but only two had sufficient data for the final report. Ohio's rate of sexual victimization in juvenile detention facilities declined nearly 23% since the last time the Justice Department surveyed juvenile facilities, from 19.8% in 2012 to 15.3%.

"No sexual victimization of youth is ever acceptable, but we are encouraged by the significant reduction in reported instances since 2012," Ohio's Department of Youth Services said in a statement to CNN.

The national rate of sexual victimization in juvenile correctional centers declined, from 9.5 percent in 2012 to 7.1 percent in 2018.

"We are seeing decreases in overall reported rates," said Erica Smith, one of the co-authors of the report. "Across the board, those rates have gone down."

The report's limitations

The report, conducted by the Bureau of Justice Statistics, came with multiple caveats.

One major limitation is that only 113 facilities of the almost 330 surveyed had enough interviews with youths in the facilities to draw usable data. The report surveyed 6,049 young people in 327 juvenile detention facilities in all 50 states and the District of Columbia over the course of 2018. The report did not include the facilities that didn't have enough usable data.

Some states allowed facilities to consent for minors to participate in the survey, while others, like Ohio, required researchers to track down guardians for permission, according to Smith. Parents could be hard to find, meaning those states tended to have less reportable data, she told CNN.

"It should be noted that we don't know for certain that Ohio has the highest rate, because only one-third of the sampled facilities were included in the rankings," according to the statement from Ohio's Department of Youth Services. "Even the report acknowledges its limitations, reiterating that the 'facilities listed as having the highest or lowest rates of sexual victimization are those among the 113 facilities that had enough completed interviews to generate reliable facility-level estimates.' This means that 214 out of 327 facilities (two-thirds) were completely omitted from the final rankings."

For states that required researchers to obtain guardian consent, Ohio's Circleville Juvenile Correctional Facility was the second-worst ranked facility in the country with 16.7% of those surveyed reported sexual abuse, down from its 2012 rate of 30.3%. Circleville's administration declined comment when contacted by CNN and referred all questions to the state.

Ohio's Department of Youth Services noted that since Circleville was surveyed in 2018, all Ohio youth correctional facilities had been outfitted with more cameras in living units. New housing units have decreased the number of youths housed together and those units have improved supervision, the statement said.

Among states that required parental consent for youth to be surveyed in the study, Macon Youth Development Campus in Georgia had the highest reported rate of sexual victimization, at 19 percent.

Georgia's Department of Juvenile Justice did not immediately respond to CNN's request for comment. In a statement to WMAZ on Wednesday, Macon Youth Development Campus spokesman Glenn Allen said, "safeguards have been put in place to screen for employees who may have the potential to victimize youth. Our staff are also trained on how to appropriately engage youth and maintain appropriate personal boundaries."

Report highlights difficulty in conducting study

Juvenile correctional facilities tend to be small, which makes it harder to do random samples, according to Smith. The Justice Department used random samples of both its sexual victimization survey and an alternative survey when evaluating a center to protect the identities of respondents. This method would grant young respondents young plausible deniability that they had not reported sexual abuse to outside authorities, Smith said.

However, according to Smith, meaningful evaluations were difficult to achieve because random sampling coupled with the small size of some facilities sometimes resulted in too few surveys.

"The very nature of these juvenile facilities makes it difficult to come up with a statistically reliable estimate about really anything that happens in these facilities," Smith said.

Seven states — Massachusetts, Nevada, North and South Carolina, North and South Dakota and Wyoming — had no reported incidents of sexual victimization in any of their surveyed juvenile facilities. However, those states were not classified as having a low rate of sexual victimization due to their relatively low response rates.

Jessica Feierman, a senior managing director with the Juvenile Law Center, an advocacy organization for youth in the justice system, said that children and young adults could still fear retaliation, hindering accurate reporting.

"Much of the time, what we find is that young people in facilities are very reluctant to share any harmful experiences they may be having," Feierman said. "I think there's always a real risk of underreporting when it comes to asking young people how they're being treated in facilities they're still in."

The report, the third of its kind, is part of the Prison Rape Elimination Act of 2003, which requires the Justice Department to track sexual victimization in prisons and other facilities.

"One sexual assault of a young person is one too many. Seven percent is incredibly high," Feierman said. "We need to ask what sort of treatment we'd want our own children to get. I'd never want to send my child to a place where there was a 7 percent chance of sexual victimization."