foreign markets when they felt able to compete globally. This push factor partially accounted for the extraordinarily high level of export growth in the 1970s, when the domestic economy slowed; increasing exports was a way for manufacturers to continue expanding despite the more sluggish domestic market. Japanese manufacturers were part of larger conglomerates, the zaibatsu, which provided financing of activities. Thus, they could concentrate on gaining high market shares, without the need to achieve high profits in the process. Exports included a wide variety of products, virtually all of which were processed to some degree. After the war, the composition of exports shifted through technological progression. Primary products, light manufactures, and crude items, which predominated during the 1950s, were gradually eclipsed by heavy industrial goods, complex machinery and equipment, and consumer durables, which required large capital investments and advanced technology to produce. This process was illustrated vividly in the case of textiles, which composed more than 30% of Japanese exports in 1960, but less than 3% by 1988. Iron and steel products, which had grown rapidly in the 1960s to become nearly 15% of exports by 1970, declined to less than 6% of exports by 1988. Over the same period, however, exports of motor vehicles rose from under 2% to over 18% of the total. In 1991 Japan's major exports were motor vehicles, office machinery, scientific and optical equipment, and semiconductors and other electronic components. After the Fukushima Nuclear Disaster in 2011 concerns were expressed about the safety of Japanese food exports. Factory output was also badly affected by power supply problems. Japanese exports have also been effected by the ongoing trade war between China and the United States and in January 2019 Japan reported an expected decline in exports. Sales of electronics and equipment used to make semiconductors have been effected as China has slowed purchases due to the combined factors of the trade war and also declining demand for smart phones. Imports During the 1960s and 1970s, imports grew in tandem with exports, at an average annual rate of 15.4% during the 1960s and 22.2% during the 1970s. In a sense, import growth over much of this period was constrained by exports, because exports generated the foreign exchange to purchase the imports. During the 1980s, however, import growth lagged far behind exports, at an average annual rate of only 2.9% from 1981 to 1988. This low level of