Average annual number of Portuguese ships moving between Europe and Asia 1500-1635

Between 1500 and 1800, the first five decades of Portuguese sea trade with East Asia saw the largest number of ships depart from Lisbon each year, before carrying capacities were gradually increased by the early 17^th century, causing the number of journeys to fall. In the early 1500s, roughly one in nine ships that departed Lisbon did not arrive at their destination, either returning home, stopping early during the trip around Africa, or being lost at sea. Additionally, for every nine ships that departed, fewer than five of these would return to Lisbon at the end of the journey. The second half of the century saw the lowest average number of departures from Lisbon, but also the smallest difference between departures and arrivals, suggesting that this was the period when trade was most efficient. Between 1600 and 1635, the number of arrivals in Lisbon was roughly a third of the number of ships that departed; it was during this period where the Dutch began to challenge Portuguese interests in Asia, therefore more ships would have been lost in conflict or required to remain in Asia and protect Portuguese trade.