Indigenous peoples are ethnic minorities who have been marginalized as their historical territories became part of a state. In international or national legislation they are generally defined as having a set of specific rights based on their historical ties to a particular territory, and to their cultural or historical distinctiveness from politically dominant populations. The concept of indigenous people may define them as particularly vulnerable to exploitation, marginalization and oppression by nations or states that may still be in the process of colonialism, or by politically dominant ethnic groups. As a result, a special set of political rights have been set to protect them by international organizations such as the United Nations, the International Labour Organization and the World Bank. The United Nations have issued a Declaration on the Rights of Indigenous Peoples to guide member-state national policies in order to protect the collective rights of indigenous peoples, such as their culture, identity, language, and access to employment, health, education and natural resources. Although no definitive definition of "indigenous peoples" exists, it is estimated that the total population of post-colonial indigenous peoples seeking human rights and discrimination redress ranges from 220 million to 350 million.