Palestinians (Arabic: الفلسطينيون, romanized: al-Filasṭīniyyūn) are an Arab national group native to the region of Palestine, descended from those who have inhabited the area over the millennia. They represent a highly homogenized community who share a cultural and ethnic identity, and close linguistic and cultural ties with other Levantine Arabs. In 1919, Palestinian Muslims and Christians constituted 90 percent of the population of Palestine, just before the third wave of Jewish immigration and the setting up of British Mandatory Palestine after World War I. Opposition to Jewish immigration spurred the consolidation of a unified national identity, though Palestinian society was still fragmented by regional, class, religious, and family differences. The history of the Palestinian national identity is a disputed issue amongst scholars. For some, the term "Palestinian" is used to refer to the nationalist concept of a Palestinian people by Palestinian Arabs from the late 19th century and in the pre-World War I period, while others assert the Palestinian identity encompasses the heritage of all eras from pre-biblical times up to the Ottoman period. After the Israeli Declaration of Independence, the 1948 Palestinian expulsion, and more so after the 1967 Palestinian exodus, the term "Palestinian" evolved into a sense of a shared future in the form of aspirations for a Palestinian state. Though the concept of Palestinian citizenship for the purpose of international law has been revived, the in fieri realization of self-determination is still insufficient, thus Palestinians remain over the threshold of eligibility to receive international protection as refugees and stateless persons. Founded in 1964, the Palestine Liberation Organization is an umbrella organization for groups that represent the Palestinian people before international states. The Palestinian National Authority, officially established in 1994 as a result of the Oslo Accords, is an interim administrative body nominally responsible for governance in Palestinian population centres in the West Bank and the Gaza Strip. Since 1978, the United Nations has observed an annual International Day of Solidarity with the Palestinian People. Despite various wars and exoduses, roughly one half of the world's Palestinian population continues to reside in the territory of former Mandatory Palestine, now encompassing Israel and the occupied Palestinian territories of the West Bank and Gaza Strip. In Israel proper, Palestinians constitute almost 21 percent of the population as part of its Arab citizens. Many are Palestinian refugees or internally displaced Palestinians, including over 1.4 million in the Gaza Strip, over 870,000 in the West Bank, and around 250,000 in Israel proper. Of the Palestinian population who live abroad, known as the Palestinian diaspora, more than half are stateless, lacking legal citizenship in any country. 2.3 million of the diaspora population are registered as refugees in neighboring Jordan, most of whom hold Jordanian citizenship; over 1 million live between Syria and Lebanon, and about 750,000 live in Saudi Arabia, with Chile holding the largest Palestinian diaspora concentration (around half a million) outside of the Arab world.