The UN’s latest World Happiness Report puts Sweden fourth on its national happiness ranking.

Finland takes the title of world’s happiest nation, for the seventh year in a row.

Sweden has consistently ended up high on this kind of list for decades, thanks to relatively strong social support, affluence, and comparatively honest and accountable governments. Its fourth place is an improvement on last year, when it came in sixth.

The United States fell out of the top 20 for the first time since the report began in 2012, getting a ranking of 23. For context, Australia was 10th, Ireland 17th, the United Kingdom 20th, Germany 24th, France 27th, China 60th and India 126th, with Afghanistan in last place.

Nordic neighbours Denmark and Norway were 2nd and 7th respectively.

The findings are drawn from Gallup World Poll data and analysed by leading wellbeing scientists, according to the World Happiness Report website.

Experts use responses from people in 143 nations to rank the world’s “happiest” countries.

Rankings are based on a three-year average of each population’s average assessment of their quality of life.

The UN report then uses experts from a range of fields including economics, psychology and sociology to attempt to explain the variations across countries and over time.

Factors such as GDP, life expectancy, having someone to count on, a sense of freedom, generosity and perceptions of corruption are among those considered in the final report.

“We found some pretty striking results. There is a great variety among countries in the relative happiness of the younger, older, and in-between populations. Hence the global happiness rankings are quite different for the young and the old, to an extent that has changed a lot over the last dozen years,” Professor John F. Helliwell, a founding editor of the World Happiness Report, said on the report’s website.