The Sustainable Development Solutions Network (SDSN) released its 2015 World Happiness Report on Thursday, ranking Cambodians’ satisfaction with their lives 145th out of 158 countries.

Cambodia was the lowest-ranked Southeast Asian country on the index, beating out only a handful of Sub-Saharan African nations, Afghanistan and Syria. The happiest nation was Switzerland, followed by Iceland and Denmark.

The report – compiled by experts across various fields, including health, economics and psychology – calculates happiness based on social measures like the amount of support respondents can depend on from family and friends, and their ability to make life decisions freely, as well as more conventional metrics like per capita GDP and healthy life expectancy.

Considering the UN’s imminent adoption of Sustainable Development Goals, the report argues, evaluating happiness – as opposed to simply economic development – is one of the keys to such sustainable development.