Australia has fallen to its lowest ranking in the World Happiness Report, as social media makes young people feel worse than ever before.The annual report ranks 140 countries on the general wellbeing of their citizens, with Australia falling to 15th in the rankings, a drop of four places from last year.The report, totalling more than 200 pages, said the mental health and wellbeing of young people in Australia had declined significantly due to the impacts of social media.JUST IN: Millions