year       Oil       Gas            Bit.           Anth.
1950       80.7      11.7           34.5           69.9
1951       76.4      11.6           32.9           70.4
1952       75.3      12.1           32.3           67.2
1953       78.5      13.9           32.0           68.3
1954       80.4      15.3           29.1           59.8
1955       78.6      15.3           28.4           53.6
1956       76.6      15.4           29.6           54.5
1957       82.1      15.7           30.2           57.9
1958       78.6      16.2           28.3           56.5
1959       74.0      17.2           27.5           51.9
1960       72.3      18.3           26.6           48.0
1961       71.8      19.6           25.8           48.8
1962       70.8      19.8           24.8           46.5
1963       69.5      20.0           24.0           49.8
1964       68.3      19.2           24.0           50.8
1965       66.3      19.1           23.5           47.5
1966       64.7      18.5           23.3           43.9
1967       63.6      18.3           23.3           43.9
1968       61.4      17.8           22.5           45.6
1969       61.4      17.4           23.0           48.7
1970       59.9      16.9           27.9           51.5
1971       60.8      17.2           30.4           53.5
1972       58.4      16.9           31.9           52.9
1973       63.5      18.7           33.6           55.7
1974      102.9      24.1           57.7           85.5
1975      105.1      32.3           65.9          109.6
1976      106.7      40.1           63.4          112.6
1977      105.5      51.6           62.3          107.4
1978      103.2      55.3           64.6           99.7
1979      133.3      66.0           64.1          106.5
1980      204.5      81.7           59.4          105.5
1981      273.6      96.0           57.4          104.0