New figures released by the US Centres for Disease Control and Prevention (CDC) show that fewer Americans are smoking than ever before, with the percentage of adult smokers aged 18 and over dropping to just 15.2 percent, a significant decrease from the 2014 figure of 16.8 percent.

Even more promisingly, the rate at which people are quitting smoking has accelerated, with the 1.6 percent drop between the 2014 and 2015 levels of adult smokers representing the steepest quitting rate in CDC statistics going back as far as 1997, when 24.7 percent of adult Americans smoked.

In fact, if that rate of quitting were to keep up for the next 10 years, by 2025 less than 13 percent of American adults would be smokers. A pretty amazing result, especially when you consider that as recently as 1965 42 percent of the adult population smoked.

The new figures are based on January to March data from the 2015 National Health Interview Survey, with the CDC defining current cigarette smokers as those who had smoked more than 100 cigarettes in their lifetime and who now smoke every day or some days.

Owing to the January to March window, the figures may contain one red herring as far as smoking goes. Since the survey period encompasses the new year, the data may be skewed slightly by the impact of new year's resolutions.

According to the statistics, 17.4 percent of adult men are current smokers, and 13 percent of adult women. Only 7.5 percent of those aged 65 and over smoke, whereas 17 percent of 18- to 44-year-olds and 16.9 percent of 45- to 64-year-olds are smokers. Hispanic adults are less likely to be smokers (10.4 percent) than non-Hispanic black (19.1 percent) and non-Hispanic white (17.1 percent) adults.

More good news is that a study published in June by researchers at the University of California, San Francisco in the US discovered that as smoking declines, existing American smokers are "softened" and are more likely to quit themselves.

The researchers found that for every 1 percent drop in the fraction of the population that smoked, the number of smokers trying to quit increased by 0.6 percent.

"It's conceivable we've reached a tipping point, and have really set in motion a cultural event in which smoking is not acceptable and not enjoyable," said Norman Edelman of the American Lung Association, who was not involved with the research, in comment to Dennis Thompson at HealthDay.