How many bale monkeys exist?

The Bale Monkey, or djam-djam, has a decreasing population - mostly due to loss and degradation of suitable habitat. As a result, they are listed as "Vulnerable" in the IUCN Red List (one step below Endangered). As of yet, however, there is a lack of formal data about the species' population and distribution, but a research papers suggest the population was less than 5000 in 2010. To protect this species, it's exceedingly important to implement conservation strategies of the bamboo forests of Ethiopia.