Read this article and answer this question The revolution in Thailand interrupted relations between France and Thailand until the 19th century, although French Jesuits were allowed to continue preaching in Thailand. After peace was achieved in 1690, Bishop Laneau was able to resume his missionary work, which he continued until his death in 1696. He was succeeded by Bishop Louis of Cice . The rest of the century consisted in persecutions by the Siamese or by the Burmese invaders. The king kept his favour for Bishops Texier de Kerlay and de Lolière-Puycontat . Between 1760 and 1765, a French group of gunners led by Chevalier Milard participated to the Burmese invasions of Siam, as an elite corps of the Burmese army. After the Burmese invasions, in 1769 Father Corre resumed missionary work in Siam, followed by Mgr Lebon . Lebon had to leave in 1775 after persecutions, but his successors Bishops Condé and Garnault returned to Siam.
How many years did the gunners led by Chevalier Milard participate in the invasions of Siam?
5