Answer based on context:

François Jarret, of Saint-Chef in the department of Isère in France, joined the company of his uncle Antoine Pécaudy de Contrecœur to battle the Iroquois in New France .  They arrived there in August 1665, and on 17 September 1669 Jarret married the twelve-year-old Marie Perrot in Île d'Orléans.  He was awarded a land grant on the south shore of the Saint Lawrence River on 29 October 1672 in a seigneury called Verchères, and thereafter continued to increase his land holdings.  The couple was to have twelve children, the fourth of whom was Marie-Madeleine, born in Verchères on 3 March 1678 and baptised that 17 April. The seigneury underwent periodic Iroquois raids.  In 1690 the matron of Verchères took command of a successful defense against an Iroquois assault on the stockade there.  By 1692 the Iroquois had killed the Jarrets' son François-Michel and two successive husbands of their daughter Marie-Jeanne. Before she performed this courageous act, she usually worked in the family field during her spare time.

How many years passed between the arrival of François Jarret and the death of his son at the hands of the Iroquis?
27