Table 2.3.—Value of the Resource, Additions, and Depletion of Gas, Present Discounted Value Method Using 3% 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			0.1		5.2
1948	5.2	.4	.2	.6	6.1
1949	6.1	.3	.2	.1	6.4
1950	6.4	.4	.2	-.1	6.6
1951	6.6	.5	.2	.1	6.9
1952	6.9	.4	.2	.2	7.3
1953	7.3	.7	.3	1.3	9.1
1954	9.1	.4	.4	1.9	11.0
1955	11.0	1.1	.5	1.8	13.4
1956	13.4	1.3	.5	.4	14.6
1957	14.6	1.1	.6	.4	15.6
1958	15.6	1.1	.7	1.6	17.7
1959	17.7	1.3	.7	.1	18.3
1960	18.3	.9	.8	2.1	20.4
1961	20.4	1.3	1.0	1.5	22.3
1962	22.3	1.6	1.1	1.3	24.1
1963	24.1	1.5	1.2	1.0	25.4
1964	25.4	1.7	1.3	-.1	25.7
1965	25.7	1.7	1.3	-.4	25.8
1966	25.8	1.6	1.3	-.7	25.3
1967	25.3	1.7	1.4	.6	26.2
1968	26.2	1.1	1.5	-.2	25.6
1969	25.6	.6	1.6	-.4	24.2
1970	24.2	3.0	1.7	1.0	26.5
1971	26.5	.8	1.8	-.4	25.1
1972	25.1	.7	1.8	-.3	23.8
1973	23.8	.5	1.8	2.5	25.0
1974	25.0	.8	1.9	6.4	30.3
1975	30.3	1.4	2.6	12.9	42.1
1976	42.1	1.5	3.9	18.8	58.5
1977	58.5	3.6	5.5	17.0	73.7
1978	73.7	3.9	6.8	15.9	86.6
1979	86.6	6.5	8.7	25.2	109.6
1980	109.6	11.7	9.4	15.0	126.9
1981	126.9	10.2	8.7	-7.2	121.2
1982	121.2	14.1	13.9	68.9	190.2
1983	190.2	18.7	20.0	97.9	286.9
1984	286.9	21.6	25.2	19.3	302.6
1985	302.6	17.3	22.8	-36.8	260.3
1986	260.3	18.1	20.1	-29.2	229.1
1987	229.1	12.6	16.9	-45.8	179.0
1988	179.0	-1.5	12.4	-46.0	119.1
1989	119.1	10.4	11.0	-3.7	114.9
1990	114.9	13.5	12.0	5.1	121.5
1991	121.5	10.3	11.8	-2.2	117.8