Table 1.4.—Value of the Resource, Additions, and Depletion of Oil, Present Discounted Value Method Using 10% Discount Rate

[Billions of current dollars]

Year	Opening stock	Additions	Depletion	Revaluation adjustment	Closing stock (1+2-3+4)
	(1)	(2)	(3)	(4)	(5)
1947			1.1		19.8
1948	19.8	3.4	1.8	4.4	25.8
1949	25.8	2.8	1.6	1.7	28.8
1950	28.8	2.5	1.8	.1	29.5
1951	29.5	4.0	2.0	-1.0	30.6
1952	30.6	2.3	1.8	-1.9	29.1
1953	29.1	2.8	2.0	1.4	31.3
1954	31.3	2.6	2.1	3.1	35.0
1955	35.0	3.0	2.5	2.5	38.0
1956	38.0	3.1	2.6	0	38.5
1957	38.5	2.4	2.6	.4	38.7
1958	38.7	2.9	2.6	2.2	41.3
1959	41.3	3.8	2.6	-3.0	39.5
1960	39.5	2.5	2.5	-.2	39.2
1961	39.2	2.7	2.5	-.6	38.8
1962	38.8	2.2	2.5	-.4	38.1
1963	38.1	2.3	2.6	.2	37.9
1964	37.9	2.7	2.6	-.5	37.5
1965	37.5	3.0	2.6	-.8	37.1
1966	37.1	2.9	2.7	-.9	36.4
1967	36.4	2.9	2.9	.7	37.1
1968	37.1	2.4	3.0	-.6	35.8
1969	35.8	2.0	3.0	-.2	34.5
1970	34.5	12.2	3.3	7.5	50.9
1971	50.9	2.5	3.6	1.0	50.8
1972	50.8	1.7	3.6	.5	49.4
1973	49.4	2.8	3.6	11.6	60.2
1974	60.2	3.6	4.7	18.8	77.9
1975	77.9	3.3	6.0	20.7	95.8
1976	95.8	3.6	7.7	14.9	106.7
1977	106.7	11.7	8.4	6.0	116.0
1978	116.0	8.8	9.2	12.2	127.7
1979	127.7	6.4	10.8	46.2	169.7
1980	169.7	15.6	14.3	69.7	240.7
1981	240.7	18.0	18.8	24.9	264.7
1982	264.7	15.7	29.2	82.9	334.1
1983	334.1	38.9	37.2	56.1	391.9
1984	391.9	44.2	35.7	-27.6	372.8
1985	372.8	33.0	32.1	-75.4	298.3
1986	298.3	13.1	24.3	-62.6	224.6
1987	224.6	20.4	18.2	-59.5	167.2
1988	167.2	9.5	11.0	-34.9	130.8
1989	130.8	9.7	11.5	21.2	150.2
1990	150.2	12.1	13.5	26.0	174.8
1991	174.8	6.1	14.9	2.5	168.5