Hongkongers are getting less happy by the year, with the city again slipping in the latest UN-backed World Happiness Report . The index ranked Hong Kong 72nd among 158 countries and territories assessed, down from 64th in the previous survey in 2013 and 46th in the first survey, published in 2012. The study is based on factors such as gross domestic product per capita and life expectancy, as well as surveys asking thousands of people their views on matters such as freedom, generosity, social support and corruption. READ MORE: China is happier, Hong Kong sadder, and Switzerland the happiest place of all While the city scores well for GDP and life expectancy, it did less well on subjective questions. Overall, it scored 5.747 on a scale of 0 to 10, with 10 being happiest. The findings echo those of studies conducted locally, including one in February by City University expert Professor Dennis Wong Sing-wing, which found Hongkongers were less happy even than during the severe acute respiratory syndrome outbreak in 2003. Wong cited political discord and the cost of housing as the biggest factors. Switzerland was the world's happiest place with a score of 7.587, just ahead of Iceland and former No 1 Denmark. Hong Kong's regional rival Singapore ranked first in Asia and 24th overall, jumping six places from the previous study. However, Hong Kong continues to fare better than mainland China, which was 84th overall with a score of 5.14, up from 93rd in the previous study. The earlier report noted that China had cut poverty as people moved to cities but "these migrants are not as happy as you would expect given the increase in their incomes. They clearly miss many aspects of rural living that raised their well-being". READ MORE: Why Hong Kong, Singapore face happiness deficit The unhappiest countries were Syria, Burundi and Togo - which also featured in the bottom 10 in the previous study. The report's authors from the UN's Sustainable Development Solutions Network said well-being and happiness were critical indicators of a nation's economic and social development, and improving happiness should be a key aim of government policy. Happiness was not about money alone, but also factors such as fairness, honesty, trust and good health, they added. "As the science of happiness advances, we are getting to the heart of what factors define quality of life for citizens," said Canadian academic Professor John Helliwell, the study's lead author. "We are encouraged that more and more governments around the world are responding with policies that put well-being first." Researchers hope the study will help world leaders when they discuss the UN's sustainable development goals in September. Correction: A previous version of this chart showed mistaken rankings for Japan and Taiwan. It has been amended to reflect the proper ranking.