Between 1950 and 1975, Finland's industry was at the mercy of international economic trends. The fast industrial growth in 1953-1955 was followed by a period of more moderate growth which started in 1956. The causes for the deceleration of growth were the general strike of 1956, as well as weakened export trends and easing of the strict regulation of Finland's foreign trade in 1957, which compelled industry to compete against ever toughening international challengers. An economic recession brought industrial output down by 3.4% in 1958. Industry, however, recovered quickly during the international economic boom that followed the recession. One reason for this was the devaluation of the Finnish markka which increased the value of the US dollar up by 39% against the Finnish markka.