Every state could have a smoking ban in restaurants, bars and workplaces by 2020, the U.S. Centers for Disease Control and Prevention (CDC) predicted this week. According to the CDC, the number of state comprehensive indoor smoking bans rose from none in 2000 to 25 by the end of 2010.

Dr. Tim McAfee, Director of the CDC’s Office of Smoking and Health, told the Associated Press (AP) that the success of the smoking ban movement seems to be growing. “I’m relatively bullish we’ll at least get close to that number,” he said.

This week’s issue of the CDC’s Morbidity and Mortality Weekly Report estimates that almost half of U.S. residents are covered by comprehensive indoor smoking bans at the state or local level, meaning they ban smoking in workplaces, bars and restaurants. An additional 10 states have laws that ban smoking in workplaces, bars or restaurants, but not all three.

While some other states have less restrictive laws, such as requiring smoking areas with separate ventilation, the CDC does not consider these laws effective in eliminating secondhand smoke exposure. The AP notes that only seven states have no indoor smoking restrictions: Indiana, Kentucky, Mississippi, South Carolina, Texas, West Virginia and Wyoming. However, some of the cities in these states do have indoor smoking laws.