Wartime rationing was officially lifted in September 1945, but prosperity did not immediately return as the next three years would witness the difficult transition back to a peacetime economy. Twelve million returning veterans were in need of work and in many cases could not find it. Inflation became a rather serious problem, averaging over 10% per year until 1950 and raw materials shortages dogged the manufacturing industry. In addition, labor strikes rocked the nation and were in some cases exacerbated by racial tensions: African-Americans that took jobs during the war were faced with irate returning veterans who demanded that they step aside. Munitions factories shut down and temporary workers returned home. Following the Republican takeover of Congress in the 1946 elections, President Truman was compelled to reduce taxes and curb government interference in the economy. With this done, the stage was set for the economic boom that, with only a few minor hiccups, would last for the next 23 years. Between 1945 and 1960, GNP grew by 250%, expenditures on new construction multiplied nine times, and consumption on personal services increased three times. By 1960, per capita income was 35% higher than in 1945, and America had entered what the economist Walt Rostow referred to as the "high mass consumption" stage of economic development. Short-term credit went up from $8.4 billion in 1946 to $45.6 billion in 1958. As a result of the postwar economic boom, 60% of the American population had attained a "middle-class" standard of living by the mid-1950s (defined as incomes of $3,000 to $10,000 in constant dollars), compared with only 31% in the last year of prosperity before the onset of the Great Depression in 1929. By the end of the decade, 87% of families owned a TV set, 75% owned a car, and 75% owned a washing machine. Between 1947 and 1960, the average real income for American workers increased by as much as it had in the previous half-century.