Sydney makes it to # 10 in our list of 10 Best Places To Live In 2011 with a Mercer score of 106.3 . The city has an average life expectancy of 80.73 years . It has a population of 4,504,469 . The city is known for tourism, entertainment and outdoor sports. Sydney has grown to become a wealthy and prosperous city, ranking as the second wealthiest city in the world in terms of per Capita purchasing power. The GDP of Switzerland is $494.6 billion . Sydney has a temperate climate with mild winters and warm winters.