All age groups in the UK are smoking less - but the largest decrease is among 18- to 24-year-olds, according to the Office of National Statistics. Why is that?
Fewer start smoking
The latest figures, for 2015, suggest one in every five (20.7%) 18- to 24-year-olds is a smoker.
In 2010, this figure was one in every four (25.8%).
Today, about 70% of 16- to 24-year-olds have never started smoking cigarettes in the first place, the data suggests - up from 46% in 1974, when records began.
And even among the age group most likely to smoke, 24- to 35-year-olds, about 60% - up from 35% in 1974 - have never picked up the habit.
Action on Smoking and Health (Ash) says: "We know that young people who try smoking are highly likely to grow up to become smokers, so the high numbers of young people reporting that they have never even tried smoking is good news."
Model Kylie Jenner was called a bad role model after she was pictured smoking on Instagram, perhaps an indicator it is no longer seen as cool.
More are quitting
The new data suggests 23.3% of 16- to 24-year-olds quit smoking in 2015, compared with 21.4% in 2010 and 13.4% in 1974.
Ash says this has been "achieved through a combination of effective legislation, policy and support for adults to quit over many decades - much of which has had a big impact on youth uptake as well as quitting".
Policy director Hazel Cheeseman says: "Creating an environment in which fewer young people try smoking and more smokers quit will protect the health of future generations and avoid hundreds and thousands of premature deaths.
"However, the achievements made to date are at risk.
"The government must urgently publish a new tobacco control plan for England and ensure this is properly funded."
The rise of vaping
In 2015, three out of every 100 16- to 24-year-olds used electronic cigarettes, up from one in every 100 in 2014, the new data suggests.
And, in total, 2.3 million people in the UK are using them - half in order to stop smoking.
But some are concerned vaping could prove a gateway to smoking for teenagers.
And critics say the fruit flavours of some e-cigarettes could make them more appealing to children.
In December 2016, the US Surgeon General said the use of e-cigarettes by children was "a major public health concern".
But Ash says the latest figures "confirm that most users are smokers or ex-smokers".
"The figures also highlight that most users are seeking to improve their health, with the most common reason for use being as an aid to quit smoking," it says.
"Where smokers make a complete switch, they can expect to significantly reduce their exposure to harmful chemicals which cause cancer and other smoking-related illnesses."
Paul Hunt, managing director of e-cigarette manufacturer V2Cigs.co.uk, said: "E-cigarettes are supporting thousands of people in quitting smoking every day.
"Information from the NHS states that people who use e-cigarettes to quit smoking can expect similar or better results than when using other nicotine replacement therapies."
"Of those people who combined NHS stop smoking support with e-cigarettes, two out of three were successful in quitting."
"As they eliminate chemicals found in regular cigarettes, such as tar, and allow people control over the amount of nicotine they're consuming, e-cigarettes are a great tool in overcoming smoking addiction."