diversified. However, the expected impacts on Brazil's current account were not to materialize until the mid-1980s. Another feature of the 1974–80 period was an acceleration of inflation. Between 1968 and 1974, the rate of inflation had declined steadily, but afterward the trend was reversed. From 16.2 percent a year in 1973, the growth rate of the general price index increased to 110.2 percent a year by 1980. Stagnation, inflation and crisis (1981–1993) The effect of the 1974–85 period's industrialization on the balance of trade was significant. The balance of trade moved from an average deficit of US$3.4 billion in the 1974–76 period to an average surplus of US$10.7 billion in the 1983–85 period. In 1985 the share of manufactures (processed and semi-processed) of total exports reached 66 percent, and between 1971–75 and 1978–83 the share of basic input imports in total imports declined from 32.3% to 19.2%. The recession and stagnation of the early 1980s had a role in reducing imports. However, import substitution was also important, as demonstrated by the few years of the 1980s that experienced a significant growth in GDP while the trade surplus was maintained. Between 1981 and 1992, the GDP increased at an average annual rate of only 2.9% and per capita income declined 6%. Gross investment, as a proportion of GDP, fell from 21 to 16 percent, in part as a result of the fiscal crisis and the loss of public-sector investment capacity. The decline also reflected growing uncertainties regarding the future of the economy. The 1980s became known as the "lost decade," and its problems spilled over into the 1990s. Despite the stagnation of the 1981–92 period, inflation remained a major problem (see stagflation). It stayed in the 100% level until the mid-80's and then grew to more than 1000% a year, reaching a record 5000% in 1993. 1981–1984 In 1979 a second oil shock nearly doubled the price of imported oil to Brazil and lowered the terms of trade further. The rise in world interest rates sharply increased Brazil's balance of payments problem and the size of the foreign debt. Nevertheless, the government continued borrowing, mainly to face an increasing debt burden, while it tried vainly to maintain the high-growth strategy. At the beginning of the 1980s, however, the foreign-debt problem became acute, leading to the introduction of a program to generate growing trade surpluses in order to service the foreign debt.