What impact did Japan 's 1973 oil crisis have on their energy use ?
The net balance on passenger transportation deteriorated from a net deficit of US$ 1.3 billion in 1985 to a net deficit of US$ 3.7 billion by 1988 , and travel ( purchases of goods and services by individuals while abroad ) increased from US$ 3.7 billion to US$ 15.8 billion over the same short time .