Utilize the input text as a context reference, choose the right relationship between halved and half from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

Sierra Leone said diamond exports nearly halved in the first half of 2015
product_or_material_produced