Utilize the input text as a context reference, choose the right relationship between Deloitte and tax 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.

Still, the natural gas industry is projected to contribute over $12 billion in tax revenues to Australia annually, Deloitte Access Economics calculated in 2012.

Answer: product_or_material_produced