Task: Question Generation
Input (English): Passage: From 1623 to 1624 the Dutch had been at war over the Pescadores, and in 1633 clashed with a fleet led by Zheng Zhilong in the Battle of Liaoluo Bay, ending in another Dutch defeat. By 1632 the Dutch had established a post on a peninsula named Tayoan , which was separated from the main part of Formosa by a shallow lagoon historically referred to as the Taikang inland sea . The Dutch fortifications consisted of two forts along the bay: the first and main fortification was the multiple-walled Fort Zeelandia, situated at the entrance to the bay, while the second was the smaller Fort Provintia, a walled administrative office. Frederick Coyett, the governor of Taiwan for the Dutch East India Company, was stationed in Fort Zeelandia with 1,800 men, while his subordinate, Valentyn, was in charge of Fort Provintia and its garrison of 500 men. In 1659, after an unsuccessful attempt to capture Nanjing, Koxinga, son of Zheng Zhilong and leader of the Ming loyalist remnants, felt that the Qing Empire had consolidated their position in China sufficiently, while his troops needed more supplies and manpower. He began searching for a suitable location as his base of operations, and soon a Chinese man named He Bin , who was working for the Dutch East India Company in Formosa , fled to Koxinga's base in Xiamen and provided him with a map of Taiwan.
Output (English): In a span of how many years were the dutch at war  over the Pescadores?