Maritime transport (or ocean transport) and fluvial transport, or more generally waterborne transport, is the transport of people (passengers) or goods (cargo) via waterways. Freight transport by sea has been widely used throughout recorded history. The advent of aviation has diminished the importance of sea travel for passengers, though it is still popular for short trips and pleasure cruises. Transport by water is cheaper than transport by air, despite fluctuating exchange rates and a fee placed on top of freighting charges for carrier companies known as the currency adjustment factor. Maritime transport accounts for roughly 80% of international trade, according to UNCTAD in 2020.