1973 oil crisis, however, caused major problems in achieving the Fourth Defence Buildup Plan (1972–76), and forced funding to be cut, raising questions about the basic concepts underlying defence policies. In 1976 the government recognized that substantial increases in spending, personnel, and bases would be virtually impossible. Instead, a "standard defence concept" was suggested, one stressing qualitative improvements in the Self-Defence Forces, rather than quantitative ones. It was decided that defence spending would focus on achieving a basic level of defence as set forth in the 1976 National Defence Program Outline. Thereafter, the government ceased to offer buildup plans that alarmed the public by their seemingly open-ended nature and switched to reliance on single fiscal year formulas that offered explicit, attainable goals. Defence spending increased slightly during the late 1970s, and in the 1980s only the defence and Official Development Assistance budgets were allowed to increase in real terms. In 1985 the Defence Agency developed the Mid-Term Defence Estimate objectives for FY 1986 through FY 1990, to improve SDF front-line equipment and upgrade logistic support systems. For the GSDF, these measures included the purchase of advanced weapons and equipment to improve antitank, artillery, ground-to-sea firepower, and mobile capabilities. For the MSDF, the focus was on upgrading antisubmarine capabilities, with the purchase of new destroyer escorts equipped with the Aegis system and SH-60J antisubmarine helicopters, and on improving antimine warfare and air defence systems. ASDF funds were concentrated on the purchase of fighter aircraft and rescue helicopters. The entire cost of the Mid-Term Defence Estimate for FY 1986 through FY 1990 was projected at approximately ¥18.4 trillion (approximately US$83.2 billion, at the 1985 exchange rate). In FY 1989, the ¥3.9 trillion defence budget accounted for 6.49% of the total budget, or 1.006% of GNP. In addition to the Defence Agency itself, the defence budget supported the Defence Facilities Administration Agency and the Security Council. Defence Agency funding covered the GSDF, the MSDF, the ASDF, the internal bureaus, the Joint Staff Council, the National Defence Academy, the National Defence Medical College, the National Institute for Defence Studies, the Technical Research and Development Institute, and the Central Procurement Office. The FY 1990 defence budget, at 0.997% of the forecast GNP, dipped below the 1% level for the first time since it was reached in 1987. But the more than ¥4.1 trillion budget still marked a 6.1% increase over the FY 1989 defence budget