Zimbabwe has been ranked the fourth unhappiest country in the world according to statistics from the World Happiness Report released today.

The country is only better than war-torn Afghanistan, Lebanon and Sierra Leone.

On 20th March every year, the world celebrates World Happiness Day and the UN Sustainable Development Solutions Network releases an annual report named World Happiness Report.

The reports measure global happiness on several standards which include national and international aspects.

Out of the 137 countries, Taliban-ruled Afghanistan has ranked last and is most unhappy according to the report. The report adds that these countries have high-level of corruption and low life expectancy.

Meanwhile, for the sixth year in a row, Finland is the world's happiest country, according to World Happiness Report rankings based largely on life evaluations from the Gallup World Poll.

The Nordic country and its neighbours Denmark, Iceland, Sweden and Norway all score very well on the measures the report uses to explain its findings: healthy life expectancy, GDP per capita, social support, low corruption, generosity in a community where people look after each other and freedom to make key life decisions.

But since we can't all move to Finland, is there something other societies can learn from these rankings?

"Is it, are they doing things that we wish we'd seen before and we can start doing? Or is it something unique about their climate and history that make them different? And fortunately, at least from my perspective, the answer is the former," said Helliwell, who is a professor emeritus at the Vancouver School of Economics, University of British Columbia.