The following symbols have been used throughout this paper:... to indicate that data are not available; -to indicate that the figure is zero or less than half the final digit shown, or that the item does not exist;-between years or months (e.g., 1990-91 or January-June) to indicate the years or months covered, including the beginning and ending years or months; / between years (e.g., 1990/91) to indicate a crop or fiscal (financial) year."Billion" means a thousand million.Minor discrepancies between constituent figures and totals are due to rounding.The term "country," as used in this paper, does not in all cases refer to a territorial entity that is a state as understood by international law and practice; the term also covers some territorial entities that are not states, but for which statistical data are maintained and provided internationally on a separate and independent basis.
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