When was the Yovel in effect?
Based on the verse “you shall proclaim freedom in the land to all its inhabitants” (Lev. 25:10), the Jubilee year was in effect only during the period when all the tribes of Israel were living in their allotted territories (Talmud, Arachin 32b)—i.e. from the time of Joshua until the time that the transJordanian tribes were exiled by the Assyrians (around 750-700 BCE). The Jubilee cycle began with Joshua’s conquest of the Holy Land in 2503 (counting from the creation). It ended with the exile of the Ten Tribes in 3205. Thus the first Jubilee was in 2552 (2503+49), and the last one was in 3202 (558 B.C.E.); it was celebrated only 14 times.
As taken from, http://www.jewishanswers.org/ask-the-rabbi-81/the-yovel/