A cruise ship or cruise liner is a passenger ship use for pleasure voyages, where the voyage itself and the ship's amenities are part of the experience. Cruising has become a major part of the tourism industry, with millions of passengers each year. The industry's rapid growth has seen nine or more newly built ships catering to a North American clientele added every year since 2001, as well as others servicing European clientele. Smaller markets such as the Asia-Pacific region are generally serviced by older tonnage displaced by new ships introduced into the high growth areas.