Given the task definition and input, reply with output. This task involves creating answers to complex questions, from a given passage. Answering these questions, typically involve understanding multiple sentences. Make sure that your answer has the same type as the "answer type" mentioned in input. The provided "answer type" can be of any of the following types: "span", "date", "number". A "span" answer is a continuous phrase taken directly from the passage or question. You can directly copy-paste the text from the passage or the question for span type answers. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words. A "number" type answer can include a digit specifying an actual value. For "date" type answers, use DD MM YYYY format e.g. 11 Jan 1992. If full date is not available in the passage you can write partial date such as 1992 or Jan 1992. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words.

Passage: Starting in the 1680s, prior to any formal colonization, the land along the shoreline of the north central coast of Saint John was occupied for decades by settlers of diverse nationalities. The property was used for maritime activities and cotton production. The Danish claimed Saint John on March 25, 1718, and the area along the north central coast from Caneel Bay to Cinnamon Bay was occupied by nine private land owners. The Danish established large sugarcane plantations worked by slaves brought from Africa. Daniel Jansen and his wife Adriana Delicat were the first land owners to acquire a formal Danish deed for property at Cinnamon Bay. Approximate to Jenson's purchase in 1718, a coastal parcel of land was purchased by William Gandy in 1722 and was later bought by Peter Durloo in 1728. Durloo was the husband of Daniel Jansen's daughter, Elizabeth. Durloo's newly acquired coastal land abutted Jensen's property to the north. In 1719, Pieter de Buyck purchased property along the north central coast of the island, east of the Gandy-Durloo land. After De Buyck's death in 1728, the land became the property of Abraham Beaudewyn. The 1936 tax records show that Jasper Jansen, Daniel and Adriana Jansen's eldest son, owned the De Buyck-Beaudewyn land. Despite the short tenure of De Buyck, this locale still carries his name, Peter Bay. These three parcels of land - the Jansen, Gandy-Durloo, and De Buyck-Beaudewyn properties - became the consolidated estate later known as Cinnamon Bay Plantation. List of new owners of the consolidated property:.
Question: How many years did William Gandy own land before it was purchased by Peter Durloo?
Answer type: Number
6.