Context: The Staten Island Ferry is the world's busiest ferry route, carrying approximately 20 million passengers on the 5.2-mile (8.4 km) route between Staten Island and Lower Manhattan and running 24 hours a day. Other ferry systems shuttle commuters between Manhattan and other locales within the city and the metropolitan area.

Question: The world's most popular ferry route is which in NYC? 
Answer: The Staten Island Ferry

Question: How many hours a day does the The Staten Island Ferry run?
Answer: 24

Question: In kilometers, how long is the Staten Island Ferry route?
Answer: 8.4

Question: Staring in State Island, in what borough does the Staten Island Ferry's route terminate?
Answer: Manhattan

Question: How many passengers ride the Staten Island Ferry annually?
Answer: 20 million