From 1970 to 1987, pollution of oxygen-binding substances was reduced by 80%, in spite of increased economic activity. Reductions were especially significant for companies discharging to state waters, reflecting the earmarking of revenues for pollution-control subsidies and the supporting activities of RIZA. Between 1970 and 1989, over 70% of industrial investments for water-pollution control were financed by subsidies provided from the state levy.