The French government allowed for the establishment of the so-called Concessionary Companies in 1889 so as to circumvent the economic non-discrimination provisions of the Treaty of Berlin and maximize the revenue drawn from underpopulated and undeveloped regions under their control. Roughly forty companies with a capital of roughly 59.5 million francs were given a free hand to exploit the colony's resources under virtual monopoly conditions. 650,000 square miles of land, except for a few strategic locations mainly around the Congo River, were leased as concessions for a thirty-year period. Cost-benefit considerations reigned supreme as often undercapitalized companies employed unqualified personnel and/or adventurers who lived off the land while stripping their concessions of all possible riches. Ivory and rubber virtually disappeared from the concessionary areas; indigenous populations were decimated by brutal forced labor, disease, and maladministration, and some fled to neighboring colonies.