The World Happiness Report is a survey of the state of global happiness and the latest edition of the report ranks 156 countries by their happiness levels, and 117 countries by the happiness of their immigrants.
The happiness level is measured by the indicators including GDP, social support, healthy life expectancy, freedom, trust and generosity as well as absence of corruption.
"There is a new top ranking country, Finland, but the top ten positions are held by the same countries as in the last two years, although with some swapping of places. Four different countries have held top spot in the four most recent reports- Denmark, Switzerland, Norway and now Finland," reads the summary.
In the latest report, Finland, which ranked fifth in the previous report, pushed Norway to the second place. Two more Nordic countries follow: Denmark and Iceland.
The other top ten countries are Switzerland, the Netherlands, Canada, New Zealand, Sweden and Australia.
The United States has slid to 18th place from 14th although it became wealthier in the meantime.
When it comes to Croatia's neighbourhood, Italy ranks 47th, Slovenia 51st, Kosovo 66th, Hungary 69th, Serbia 78th, Montenegro 81st and Bosnia and Herzegovina 93rd.
The document was released by the United Nations on 14 March "at a launch event at the Pontifical Academy of Sciences in the Vatican." A subsequent event will occur next week on March 20, celebrating International Day of Happiness at the United Nations.