Apart from the growing investment effort, which included capital transfers to the public enterprises, government expenditure patterns since the revolution reflected rapid expansion in the number of civil servants and pressure to redistribute income, mainly through current transfers and subsidies, as well as burgeoning interest obligations. The category "current transfers" nearly tripled its share of GDP between 1973 and 1990, from under 5 percent to 13.4 percent, reflecting the explosive growth of the social security system, both with respect to the number of persons covered and the upgrading of benefits. Escalating interest payments on the public debt, from less than half a percent of GDP in 1973 to 8.2 percent of GDP in 1990, were the result of both a rise in the debt itself and higher real effective interest rates.