The population went into severe decline in the 1870s, possibly from disease. The Dutch sent medical officers to investigate. Since the island's highest point is only above sea level, it would have been severely affected by the tsunami associated with the Krakatoa eruption in 1883, as well as by the massive volcanic debris. The indigenous population failed to recover and numbered only about 400 people in the early 1960s. Therefore, the Indonesian government uses the island for rehabilitation of juvenile offenders from Java, who perform forced labor, clearing bush and constructing rice fields. As noted above, the population has expanded considerably since that time, and reached 4,035 at the 2020 Census.