Australia has slipped out of the top 10 happiest countries in the world, according to the University of Oxford's global happiness ranking. Finland claimed the top spot for the eighth year in a row, while Australia landed at number 11. The ranking is based on three-year averages of self-reported wellbeing scores from 147 countries. Factors such as wealth, health, generosity, social support, and household size were found to influence overall happiness levels. The US also experienced a sharp drop in its ranking, landing at its lowest ever position at number 24.