Table A4.  Approximate Heat Content of Natural Gas, 1949-2007
                      (Btu per Cubic Foot)


Year		 Production Consumption 1

Imports

Exports
Marketed Dry End-Use Sectors 2 Electric Power Sector 3 Total
1949
 1,120 1,035 1,035 1,035 1,035 – – 1,035
1950
 1,119 1,035 1,035 1,035 1,035 – – 1,035
1951
 1,114 1,035 1,035 1,035 1,035 – – 1,035
1952
 1,115 1,035 1,035 1,035 1,035 1,035 1,035
1953
 1,116 1,035 1,035 1,035 1,035 1,035 1,035
1954
 1,115 1,035 1,035 1,035 1,035 1,035 1,035
1955
 1,120 1,035 1,035 1,035 1,035 1,035 1,035
1956
 1,116 1,035 1,035 1,035 1,035 1,035 1,035
1957
 1,113 1,035 1,035 1,035 1,035 1,035 1,035
1958
 1,110 1,035 1,035 1,035 1,035 1,035 1,035
1959
 1,109 1,035 1,035 1,035 1,035 1,035 1,035
1960
 1,107 1,035 1,035 1,035 1,035 1,035 1,035
1961
 1,108 1,035 1,035 1,035 1,035 1,035 1,035
1962
 1,107 1,035 1,035 1,035 1,035 1,035 1,035
1963
 1,103 1,031 1,031 1,031 1,031 1,031 1,031
1964
 1,102 1,032 1,032 1,032 1,032 1,032 1,032
1965
 1,101 1,032 1,032 1,032 1,032 1,032 1,032
1966
 1,103 1,033 1,033 1,033 1,033 1,033 1,033
1967
 1,105 1,032 1,032 1,032 1,032 1,032 1,032
1968
 1,115 1,031 1,031 1,031 1,031 1,031 1,031
1969
 1,103 1,031 1,031 1,031 1,031 1,031 1,031
1970
 1,102 1,031 1,031 1,031 1,031 1,031 1,031
1971
 1,103 1,031 1,031 1,031 1,031 1,031 1,031
1972
 1,100 1,027 1,027 1,027 1,027 1,027 1,027
1973
 1,093 1,021 1,020 1,024 1,021 1,026 1,023
1974
 1,097 1,024 1,024 1,022 1,024 1,027 1,016
1975
 1,095 1,021 1,020 1,026 1,021 1,026 1,014
1976
 1,093 1,020 1,019 1,023 1,020 1,025 1,013
1977
 1,093 1,021 1,019 1,029 1,021 1,026 1,013
1978
 1,088 1,019 1,016 1,034 1,019 1,030 1,013
1979
 1,092 1,021 1,018 1,035 1,021 1,037 1,013
1980
 1,098 1,026 1,024 1,035 1,026 1,022 1,013
1981
 1,103 1,027 1,025 1,035 1,027 1,014 1,011
1982
 1,107 1,028 1,026 1,036 1,028 1,018 1,011
1983
 1,115 1,031 1,031 1,030 1,031 1,024 1,010
1984
 1,109 1,031 1,030 1,035 1,031 1,005 1,010
1985
 1,112 1,032 1,031 1,038 1,032 1,002 1,011
1986
 1,110 1,030 1,029 1,034 1,030 997 1,008
1987
 1,112 1,031 1,031 1,032 1,031 999 1,011
1988
 1,109 1,029 1,029 1,028 1,029 1,002 1,018
1989
 1,107 1,031 1,031 1 1,028 1,031 1,004 1,019
1990
 1,105 1,029 1,030 1,027 1,029 1,012 1,018
1991
 1,108 1,030 1,031 1,025 1,030 1,014 1,022
1992
 1,110 1,030 1,031 1,025 1,030 1,011 1,018
1993
 1,106 1,027 1,028 1,025 1,027 1,020 1,016
1994
 1,105 1,028 1,029 1,025 1,028 1,022 1,011
1995
 1,106 1,026 1,027 1,021 1,026 1,021 1,011
1996
 1,109 1,026 1,027 1,020 1,026 1,022 1,011
1997
 1,107 1,026 1,027 1,020 1,026 1,023 1,011
1998
 1,109 1,031 1,033 1,024 1,031 1,023 1,011
1999
 1,107 1,027 1,028 1,022 1,027 1,022 1,006
2000
 1,107 1,025 1,026 1,021 1,025 1,023 1,006
2001
 1,105 1,028 1,029 1,026 1,028 1,023 1,010
2002
 1,106 1,027 1,029 1,020 1,027 1,022 1,008
2003
 1,106 1,031 1,033 1,025 1,031 1,025 1,009
2004
 1,105 1,027 1,027 1,027 1,027 1,025 1,009
2005
 R 1,105 1,029 1,029 1,028 1,029 1,025 1,009
2006
 R 1,103 R 1,028 R 1,028 1,028 R 1,028 1,025 1,009
2007
 E 1,103 E 1,028 E 1,028 P 1,028 E 1,028 E 1,025 E 1,009
1Consumption factors are for natural gas, plus a small amount of supplemental gaseous fuels. R=Revised.  P=Preliminary.  E=Estimate.  – – = Not applicable.  
2Residential, commercial, industrial, and transportation sectors. Note:  The values in this table are for gross heat contents.  See "Heat Content" in Glossary. 
3Electricity-only and combined-heat-and-power (CHP) plants within the NAICS 22 category whose
primary business is to sell electricity, or electricity and heat, to the public.  Through 1988, data are for
electric utilities only; beginning in 1989, data are for electric utilities and independent power producers.		 Sources:  See "Thermal Conversion Factor Source Documentation," which follows Table A6.