HANOI, March 21 (Xinhua) -- Vietnam moved up one spot from last year to rank 94th out of 156 countries and regions by their happiness level this year, according to the United Nation's annual World Happiness Report published on Thursday.

Finland topped the list for the second year in a row, tailed by Denmark, Norway and Iceland, respectively. On the contrary, South Sudan ranked the least happy on the list.

Happiness levels were evaluated based on six key well-being variables, namely gross domestic product per capita, social support, healthy life expectancy, freedom to make life choices, generosity and freedom from corruption, according to the report.