"Proven crude oil reserves in the foreign non-Communist world were estimated to be just under 41 billion barrels at the end of 1948; they had increased sixfold to 250 billion barrels by 1962 and then more than doubled this amount to 522 billion barrels by 1972. This increase over a twenty-four-year period was equivalent to an average annual compound growth rate of 11.2 percent—a spectacular expansion of the non-Communist world’s oil stock outside the United States and Canada."