Even though adults are smoking fewer cigarettes overall, some racial and ethnic groups are smoking at pretty high rates.

A new federal study showed that American-Indians and Alaskan natives had the highest prevalence of cigarette smoking at nearly 40 percent of their population. That is compared to nearly 25 percent among whites and African-Americans, according to a study released Thursday by the Centers for Disease Control and Prevention.

The smoking rate for African-Americans and whites have declined from previous studies, the CDC found. In 2002-2005, the rate was about 27 percent for both groups. From 2010-2013, the rates declined to around 25 percent, the study showed.

Asians had the lowest smoking rate at nearly 10 percent.

Prior studies pegged the overall smoking rate in 2014 to be nearly 17 percent of the population.

The study looked at cigarette smoking for racial and ethnic groups during 2010-2013. The findings could influence how to employ certain tools to curb smoking.

"Looking beyond broad racial and ethnic population categories can help better focus the strategies that we know work to reduce tobacco use among sub-groups with higher rates of use," said Bridgette Garrett, associate director for health equity in the CDC's Office on Smoking and Health.

The CDC pointed to certain tools such as media campaigns, higher prices for cigarettes and promotion of quitting programs at the doctor's office that can help reduce tobacco.