As the capital of Poland, Warsaw is also the country’s largest city, with a population of 1.7 million and an area of just over 500 square km. It is a vital economic centre for Poland. There were 324,282 companies registered in Warsaw at the end of 2008, accounting for some 13.5% of GDP. The most important sector is services, including trade and repair, transport and storage, accommodation and catering, financial services and real estate activities, which collectively accounted for about 84% of the city’s economic activity in 2006. By contrast, industrial production and construction accounted for shares of just 11.7% and 4.1% respectively. Warsaw ranks 16th overall in the European Green City Index. Its score of 59.04 out of 100 is supported by the city’s strong economic reliance on services. Warsaw outperforms most other medium-sized cities in categories such as air quality and transport. Its best performance is in the environmental governance category, where it is ranked in joint fifth place.