( 1 ) source : our estimates are based on a combination of data obtained from publicly available sources including the international monetary fund , united nations , department of economic and social affairs , cruise lines international association ( "clia" ) and g.p . wild . ( 2 ) our estimates include the united states and canada . ( 3 ) our estimates include european countries relevant to the industry ( e.g. , nordics , germany , france , italy , spain and the united kingdom )