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.
Text: Prior to 2012, oil exports provided half the Iranian government's revenue and made up one-fifth of the country's GDP; its exports have been more than halved since.
user
product_or_material_produced
assistant