Paris for 31 percent of the GDP of France. According to the Economist Intelligence Unit Worldwide Cost of Living Survey in 2018, Paris was the second-most expensive city in the world, behind Singapore and ahead of Zurich, Hong Kong, Oslo and Geneva. The city is a major rail, highway, and air-transport hub served by two international airports: Paris-Charles de Gaulle (the second busiest airport in Europe after London Heathrow Airport with 69.5 million passengers in 2017) and Paris-Orly. Opened in 1900, the city's subway system, the Paris Métro, serves 5.23 million passengers daily, and is the second busiest metro system in
Bamako–Sénou International Airport Bamako–Sénou International Airport Bamako's Modibo Keita International Airport (formerly Bamako–Sénou International Airport) is Mali's main airport located approximately south of downtown Bamako, the capital of Mali in West Africa. It is country's only international airport. It is managed by Aéroports du Mali (ADM). Its operations are overseen by the Malian Ministry of Equipment and Transport. Bamako-Sénou Airport was opened to traffic in 1974. The airport was upgraded between 2007 and 2012 in a US$181 million project funded by the Millennium Challenge Corporation, a United States foreign aid agency. Bamako–Sénou International Airport is adjacent to Air Base 101, which is used