Final answer:
In 2013, there were approximately 200,000 Western gorillas and 6,000 Eastern gorillas. The estimated numbers for the Sumatran orangutan and the bonobo were 6,000 and 10,000 respectively.
Step-by-step explanation:
The estimated number of Western (lowland) gorillas in 2013 was 200,000, while the estimated number of Eastern (mountain) gorillas was 6,000. For the Sumatran orangutan, the estimated number is 6,000, and for the bonobo, the estimated number is 10,000.