Indonesia has, in the past few years, made attempts to liberalize its foreign trade, but unanticipated problems arose preventing substantial progress. Most tariffs are designed to stimulate exports and to protect infant domestic industries. However, the tariff system is burdensome and time consuming and evasion is widespread. Exempt from import duties are raw materials and manufactured items imported for use in government-backed or approved labor-intensive enterprises. Duties on imports from ASEAN member countries were lowered to 20% in 1978. Two years later, duties on 384 products—including cement, sarongs, engine pistons, cameras, and telecommunications equipment— were reduced or abandoned, regardless of origin. Many items may only be imported by government-approved importers and there are quotas for certain non-durable goods. A three-tiered tariff structure, with rates of 0%, 5%, of 10 % applied to various commodities, has been implemented to satisfy Indonesia's IMF commitments. An import sales tax is imposed on imports at point of entry (except for those goods considered essential by the government) at rates of 5–30%. Distilled spirits are dutied at a rate of 170% and vehicle taxes range from 5% for trucks up to 75% for some sedans. Indonesia has also committed to the ASEAN Free Trade Agreement and its Common Effective Preferential Tariff (CEPT), and is further liberalizing its trade in order to meet the provisions of that compact. There is a free trade zone on Batam Island that is exempt from all import and export taxes; a free trade facility near Tanjung Priok, the country's main port; a bonded warehouse in Cakung, near Jakarta; and a number of other export processing zones.