Question: How many children work year round in the continent that contains the river that serves as drainage for the southwest plain of the Congo?

full_context: Document 1: Republic of the Congo: The Republic of the Congo (French: République du Congo), also known as Congo, Congo Republic, West Congo[citation needed], or Congo-Brazzaville, is a country located in Central Africa. It is bordered by five countries: Gabon to the west; Cameroon to the northwest; the Central African Republic to the northeast; the Democratic Republic of the Congo to the east and south; and the Angolan exclave of Cabinda to the southwest.
Document 2: Geography of Angola: Angola is located on the western Atlantic Coast of Central Africa between Namibia and the Republic of the Congo. It also is bordered by the Democratic Republic of the Congo and Zambia to the east. The country consists of a sparsely watered and somewhat sterile coastal plain extending inland for a distance varying from . Slightly inland and parallel to the coast is a belt of hills and mountains and behind those a large plateau. The total land size is . It has an Exclusive Economic Zone of .
Document 3: Mayombe: Mayombe (or Mayumbe) is a geographic area on the western coast of Africa occupied by low mountains extending from the mouth of the Congo River in the south to the Kouilou-Niari River to the north. The area includes parts of the Democratic Republic of the Congo, Angola (Cabinda Province), the Republic of the Congo and Gabon.
Document 4: Child labour: Systematic use of child labour was common place in the colonies of European powers between 1650 and 1950. In Africa, colonial administrators encouraged traditional kin-ordered modes of production, that is hiring a household for work not just the adults. Millions of children worked in colonial agricultural plantations, mines and domestic service industries. Sophisticated schemes were promulgated where children in these colonies between the ages of 5–14 were hired as an apprentice without pay in exchange for learning a craft. A system of Pauper Apprenticeship came into practice in the 19th century where the colonial master neither needed the native parents' nor child's approval to assign a child to labour, away from parents, at a distant farm owned by a different colonial master. Other schemes included 'earn-and-learn' programs where children would work and thereby learn. Britain for example passed a law, the so-called Masters and Servants Act of 1899, followed by Tax and Pass Law, to encourage child labour in colonies particularly in Africa. These laws offered the native people the legal ownership to some of the native land in exchange for making labour of wife and children available to colonial government's needs such as in farms and as picannins.
Document 5: Republic of the Congo: The southwest of the country is a coastal plain for which the primary drainage is the Kouilou-Niari River; the interior of the country consists of a central plateau between two basins to the south and north. Forests are under increasing exploitation pressure.
Document 6: Geography of Cambodia: Cambodia's low mountain ranges - representing the walls of the bowl - remain as the result of only rather recent substantial infrastructural development and economic exploitation - in particular in remote areas - formidably forested. The country is fringed to the north by the Dangrek Mountains plateau, bordering Thailand and Laos, to the north - east by the Annamite Range, in the south - west by the Cardamom Mountains and in the South by the Elephant Mountains. Highlands to the north - east and to the east merge into the Central Highlands and the Mekong Delta lowlands of Vietnam.
Document 7: Congo River: Railways now bypass the three major falls, and much of the trade of Central Africa passes along the river, including copper, palm oil (as kernels), sugar, coffee, and cotton. The river is also potentially valuable for hydroelectric power, and the Inga Dams below Pool Malebo are first to exploit the Congo river.
Document 8: Child labour: Children working at a young age has been a consistent theme throughout Africa. Many children began first working in the home to help their parents run the family farm. Children in Africa today are often forced into exploitative labour due to family debt and other financial factors, leading to ongoing poverty. Other types of domestic child labour include working in commercial plantations, begging, and other sales such as boot shining. In total, there is an estimated five million children who are currently working in the field of agriculture which steadily increases during the time of harvest. Along with 30 percent of children who are picking coffee, there are an estimated 25,000 school age children who work year round.
Document 9: Child labour: Other legal factors that have been implemented to end and reduce child labour includes the global response that came into force in 1979 by the declaration of the International Year of the Child. Along with the Human Rights Committee of the United Nations, these two declarations worked on many levels to eliminate child labour. Although many actions have been taken to end this epidemic, child labour in Africa is still an issue today due to the unclear definition of adolescence and how much time is needed for children to engage in activities that are crucial for their development. Another issue that often comes into play is the link between what constitutes as child labour within the household due to the cultural acceptance of children helping run the family business. In the end, there is a consistent challenge for the national government to strengthen its grip politically on child labour, and to increase education and awareness on the issue of children working below the legal age limit. With children playing an important role in the African economy, child labour still plays an important role for many in the 20th century.
Document 10: Yumbi: Yumbi is a town and territory in Plateaux District of Bandundu Province in the Democratic Republic of the Congo. It lies on the eastern bank of the Congo River between Bolobo and Lukolela.
Document 11: Republic of the Congo: Congo is located in the central-western part of sub-Saharan Africa, along the Equator, lying between latitudes 4°N and 5°S, and longitudes 11° and 19°E. To the south and east of it is the Democratic Republic of Congo. It is also bounded by Gabon to the west, Cameroon and the Central African Republic to the north, and Cabinda (Angola) to the southwest. It has a short coast on the Atlantic Ocean.
Document 12: Child labour: Small-scale artisanal mining of gold is another source of dangerous child labour in poor rural areas in certain parts of the world. This form of mining uses labour-intensive and low-tech methods. It is informal sector of the economy. Human Rights Watch group estimates that about 12 percent of global gold production comes from artisanal mines. In west Africa, in countries such as Mali - the third largest exporter of gold in Africa - between 20,000 and 40,000 children work in artisanal mining. Locally known as orpaillage, children as young as 6 years old work with their families. These children and families suffer chronic exposure to toxic chemicals including mercury, and do hazardous work such as digging shafts and working underground, pulling up, carrying and crushing the ore. The poor work practices harm the long term health of children, as well as release hundreds of tons of mercury every year into local rivers, ground water and lakes. Gold is important to the economy of Mali and Ghana. For Mali, it is the second largest earner of its export revenue. For many poor families with children, it is the primary and sometimes the only source of income.
Document 13: Republic of the Congo: The Republic of the Congo's sparse population is concentrated in the southwestern portion of the country, leaving the vast areas of tropical jungle in the north virtually uninhabited. Thus, Congo is one of the most urbanized countries in Africa, with 70% of its total population living in a few urban areas, namely in Brazzaville, Pointe-Noire or one of the small cities or villages lining the 534-kilometre (332 mi) railway which connects the two cities. In rural areas, industrial and commercial activity has declined rapidly in recent years, leaving rural economies dependent on the government for support and subsistence.
Document 14: Mitumba Mountains: The Mitumba Mountain range stretches along the Western Rift Valley in Eastern Congo (DRC), west of lake Tanganyika. The two main peaks, Mount Kahuzi (3,308 m) and Mount Biéga (2,790 m) are extinct volcanoes.
Document 15: Child labour: In developing countries, with high poverty and poor schooling opportunities, child labour is still prevalent. In 2010, sub-saharan Africa had the highest incidence rates of child labour, with several African nations witnessing over 50 percent of children aged 5–14 working. Worldwide agriculture is the largest employer of child labour. Vast majority of child labour is found in rural settings and informal urban economy; children are predominantly employed by their parents, rather than factories. Poverty and lack of schools are considered as the primary cause of child labour.
ground_truth: estimated 25,000
sub_queries: Which river serves as drainage for the southwest plain of the Congo? Answer: Kouilou-Niari River
Kouilou-Niari River >> continent Answer: Africa
How many children work year round in Africa ? Answer: estimated 25,000