In Israel the reintroduction program was established in 1978 when four pairs of Arabian oryx were purchased.[citation needed] At this time the IUCN Redbook reported wild populations totaling 90-100 animals in 3 locations in Northern Arava and the Negev Desert. As of 2014 there are there are around 130 animals in the Aravah, and in 2013 they began to spread to the central Negev and the population keeps increasing. In addition to the natural population increase, every year around six animals are released to the wild in Israel.