Led by US economist Jeffrey Sachs, the SDSN, an initiative under the United Nations, produces a report every 18 months based on data from the Gallup World Poll.

The latest analysis, based on data between 2012 and 2014, saw the first change on top as Switzerland replaced Denmark in first spot. Denmark fell to 3rd behind Iceland.

The top ten group of countries with the world's happiest people also comprises Norway, Canada, Finland, Sweden, New Zealand and Australia.

Bottoming the list are Togo, Burundi, Rwanda, Syria and Benin.

In compiling the list, the survey takes into account a variety of factors such as GDP, life expectancy, perception of corruption and personal freedoms, charity and generosity of people in each country.

Using a different methodology, the first report was published in 2012 after 20 March was designated International Day of Happiness by the UN General Assembly.