mid 19th to early 20th centuries, among other things tied to the role of Switzerland during the World Wars. Switzerland's total energy consumption, which was dropping from the mid 1910s to the early 1920s, started to increase again in the early 1920s. It stagnated during the 1930s before falling again during the early 1940s; but rapid growth started once again in the mid 1940s. In the 1940s, particularly during World War II, the economy profited from the increased export and delivery of weapons to Germany, France, the United Kingdom, and other European countries. However, Switzerland's energy consumption decreased rapidly. The co-operation of the banks with the Nazis (although they also co-operated extensively with the British and French) and their commercial relations with the Axis powers during the war were later sharply criticised, resulting in a short period of international isolation of Switzerland. Switzerland's production facilities were largely undamaged by the war, and afterwards both imports and exports grew rapidly. In the 1950s, annual GDP growth averaged 5% and Switzerland's energy consumption nearly doubled. Coal lost its rank as Switzerland's primary energy source, as other imported fossil fuels, such as crude and refined oil and natural and refined gas, increased. In the 1960s, annual GDP growth averaged 4% and Switzerland's total energy consumption nearly doubled again. By the end of the decade oil provided over three-quarters of Switzerland's energy. In the 1970s the GDP growth rate gradually declined from a peak of 6.5% in 1970; GDP then contracted by 7.5% in 1975 and 1976. Switzerland became increasingly dependent on oil imported from its main suppliers, the OPEC cartel. The 1973 international oil crisis caused Switzerland's energy consumption to decrease in the years from 1973 to 1978. In 1974 there were three nationwide car-free Sundays when private transport was prohibited as a result of the oil supply shock. From 1977 onwards GDP grew again, although Switzerland was also affected by the 1979 energy crisis which resulted in a short-term decrease in Switzerland's energy consumption. In 1970 industry still employed about 46% of the labor force, but during the economic recession of the 1970s the services sector grew to dominate the national economy. By 1970 17.2% of the population and about one quarter of the work force were foreign nationals, though job losses during the economic recession decreased this number. In the 1980s, Switzerland's economy contracted by 1.3% in 1982 but grew substantially