Passage: Consensus has determined sea turtles, including E. imbricata to be, at the very least, threatened species because of their slow growth and maturity, and slow reproductive rates. Many adult turtles have been killed by humans, both accidentally and deliberately. Their existence is threatened due to pollution and loss of nesting areas because of coastal development. Biologists estimate that the hawksbill population has declined 80 percent in the past 100–135 years. Human and animal encroachment threatens nesting sites, and small mammals dig up the eggs to eat. In the US Virgin Islands, mongooses raid hawksbill nests (along with those of other sea turtles, such as Dermochelys coriacea) right after they are laid.In 1982, the  IUCN Red List of Threatened Species first listed  E. imbricata as Endangered. This endangered status continued through several reassessments in 1986, 1988, 1990, and 1994 until it was upgraded in status to  Critically Endangered in 1996. Two petitions challenged its status as an endangered species prior to this, claiming the turtle (along with three other species) had several significant stable populations worldwide. These petitions were rejected based on their analysis of data submitted by the Marine Turtle Specialist Group (MTSG). The data given by the MTSG showed the worldwide hawksbill sea turtle population had declined by 80% in the three most recent generations, and no significant population increase occurred as of 1996. CR A2 status was denied, however, because the IUCN did not find sufficient data to show the population likely to decrease by a further 80% in the future.The species (along with the entire family Cheloniidae) has been listed on Appendix I of the Convention on International Trade in Endangered Species. It is prohibited to import or export turtle products, or to kill, capture, or harass hawksbill sea turtles.Local involvement in conservation efforts has also increased in the past few years.

Question: How many tries did people use to challenge the legitimacy of the endangerment of the turtle?
Two