Smoking rates in the U.S. have hit an all-time low, with only about 16.8 percent of adults smoking cigarettes in 2014 - a near 20 percent drop from the smoking rate in 2005.

A new report released by the Centers for Disease Control and Prevention (CDC) Thursday shows that the smoking rate among adults was 16.8 percent in 2014, down from 20.9 percent in 2005 and 17.8 percent in 2013, reported The Los Angeles Times. The figure is the lowest recorded since the agency began tracking cigarette smoking.

The average number of cigarettes smoked daily also declined, falling from 16.7 in 2005 to 13.8 in 2014, according to the study.

Adults between the ages of 18 and 24 experienced the largest decrease in cigarette consumption.

The CDC said that the declining rates could be a direct result of media campaigns, new laws and accessible quitting solutions, although the report notes that the dwindling numbers could be due to increased interest in alternative smoking methods such as e-cigarettes, according to UPI.

The report highlights that quitting smoking has been more difficult for several demographics, most notably the poor. The smoking rate for those on Medicaid, the federally funded health care program for low-income Americans, stood at 29.1 percent in 2014. That's compared to only 12.9 percent of adults on private health insurance who continued to smoke cigarettes. As for the uninsured, 27.9 percent smoked.

Among adults earning below the federal poverty level of $19,790 per year, 26.3 percent smoked.

Rates remained especially high for adults with a general education development certificate, or GED, with 43 percent smoking, compared to only five percent of adults with a graduate degree.

The smoking rate among adults 25-44 was higher than the overall smoking rate, at 20 percent.

Nearly 28 percent of multiracial adults smoked, and the rate among lesbian, gays, or bisexuals stood at 23.9 percent.

"Disparities are the single most important issue in smoking," Kenneth Warner, a professor at the University of Michigan School of Public Health, told The New York Times. "The people who are politically influential believe the smoking problem has been solved. It's not in their neighborhoods. Their friends don't smoke. Those who still smoke are the poor, the disenfranchised, the mentally ill. That's who we need to focus on."

Smoking still kills nearly half a million Americans each year and costs more than $300 billion annually, according to the report. Along with anti-smoking mass media campaigns, the CDC said other proven solutions must still be implemented, "including higher tobacco taxes, strong smoke-free laws, well-funded tobacco prevention and cessation programs that include mass media campaigns, and comprehensive, barrier-free health insurance coverage for smoking cessation treatments."

The report came the same day federal authorities proposed a ban on smoking in public housing, which would affect more than 700,000 homes if implemented, according to TIME.

"We have a responsibility to protect public housing residents from the harmful effects of secondhand smoke," said HUD Secretary Julian Castro. "This proposed rule will help improve the health of more than 760,000 children and help public housing agencies save $153 million every year in health care, repairs and preventable fires."