Paris is an important crossroads between Germany, Belgium, Luxembourg and the UK, principally because of its location and a high-speed train network. The Paris metropolitan area and the greater Paris region (Ile-de-France) together form the most densely populated part of France, with nearly 12 million inhabitants. It is the second-largest city in the European Green City Index after Istanbul. The economy is shifting steadily towards services, including finance and information technology, but Paris remains an important manufacturing zone. Paris ranks tenth overall in the index, scoring 73.21 out of 100, second only to Berlin within the group of large cities. Its environmental performance is particularly strong in the carbon dioxide (CO2) emissions, buildings, water and green governance categories.