According to an annual World Happiness Report released Thursday, Switzerland has the world's happiest people.

The report was produced by the Sustainable Development Solutions Network (SDSN), which measured happiness and well-being levels in 158 countries. After Switzerland Denmark, Norway and Canada followed in the rankings that measured. Most unhappy people lived in Togo, Burundi, Syria, Benin and Rwanda.

Jeffrey Sachs, director of the Earth Institute at Columbia University in New York said, “The aspiration of society is the flourishing of its members. This report gives evidence on how to achieve societal well-being. It's not by money alone, but also by fairness, honesty, trust and good health”.

In 2012, the United Nations General Assembly established the International Day of Happiness to recognize the importance of happiness and well-being as universal goals and aspirations in the lives of people around the world.

First study was released was in 2012, which looked at factors that determine most of the variations in people's well-being over time and among countries. Such factors include a healthy life expectancy, the presence of social support systems, freedom to make choices and gross domestic product (GDP) per capita.

Researchers broke down the data by gender, age and region for the first time. The findings revealed that women's assessments of their happiness on average were slightly higher than those of men. The research also found that young people tend to happier than older people globally.

Although the ranking has changed, the report found that nine of the top 10 countries were also at the top in the 2013 study this year. In 2013, Denmark held the top spot.

Changes in how people evaluated their lives comparing data from the 2005-2007 period to 2012-2014 showed the impact of the global financial crisis on national happiness.