countries, it ranks among the lowest in international measurements of government transparency, civil liberties and quality of life. The population is young and predominantly rural; Rwanda has one of the youngest populations in the world. Rwandans are drawn from just one cultural and linguistic group, the Banyarwanda. However, within this group there are three subgroups: the Hutu, Tutsi and Twa. The Twa are a forest-dwelling pygmy people and are often considered descendants of Rwanda's earliest inhabitants. Christianity is the largest religion in the country; the principal and national language is Kinyarwanda, spoken by native Rwandans, with English, French and Swahili serving as additional official languages. The economy is based mostly on subsistence agriculture. Coffee and tea are the major cash crops for export. Tourism is a fast-growing sector and is now the country's leading foreign exchange earner. In the 21st century, Rwanda has been described as an emerging tech hub for Africa, with an increase of start-up companies. The country is a member of the African Union, the United Nations, the Commonwealth of Nations, COMESA, OIF and the East African Community. In June 2022, the country hosted the Commonwealth Heads of Government Meeting (CHOGM) originally scheduled for 2020, when it was cancelled due to the COVID-19 pandemic. History Modern human settlement of what is now Rwanda dates from, at the latest, the last glacial period, either in the Neolithic period around 8000 BC, or in the long humid period which followed, up to around 3000 BC. Archaeological excavations have revealed evidence of sparse settlement by hunter-gatherers in the late Stone Age, followed by a larger population of early Iron Age settlers, who produced dimpled pottery and iron tools. These early inhabitants were the ancestors of the Twa, aboriginal pygmy hunter-gatherers who remain in Rwanda today. Between 700 BC and 1500 AD, a number of Bantu groups migrated into Rwanda, clearing forest land for agriculture. The forest-dwelling Twa lost much of their habitat and moved to the mountain slopes. Historians have several theories regarding the nature of the Bantu migrations; one theory is that the first settlers were Hutu, while the Tutsi migrated later to form a distinct racial group, possibly of Nilo-hamitic origin. An alternative theory is that the migration was slow and steady, with incoming groups integrating into rather than conquering the existing society. Under this theory, the Hutu and Tutsi distinction arose later and was a class distinction