Table 2.7  Type of Heating in Occupied Housing Units, Selected Years, 1950-2005
Year	Coal 1	Distillate Fuel Oil	Kerosene	Liquefied Petroleum Gases	Natural Gas	Electricity	Wood	Solar	Other 2	None 3	Total
	Millions
1950	14.48	9.46	[4]	0.98	11.12	0.28	4.17	NA	0.77	1.57	42.83
1960	6.46	17.16	[4]	2.69	22.85	.93	2.24	NA	.22	.48	53.02
1970	1.82	16.47	[4]	3.81	35.01	4.88	.79	NA	.27	.40	63.45
1973	.80	17.24	[4]	4.42	38.46	7.21	.60	NA	.15	.45	69.34
1974	.74	16.84	[4]	4.14	39.47	8.41	.66	NA	.09	.48	70.83
1975	.57	16.30	[4]	4.15	40.93	9.17	.85	NA	.08	.47	72.52
1976	.48	16.45	[4]	4.24	41.22	10.15	.91	NA	.09	.46	74.01
1977	.45	15.62	.44	4.18	41.54	11.15	1.24	NA	.15	.51	75.28
1978	.40	15.65	.42	4.13	42.52	12.26	1.07	NA	.12	.60	77.17
1979	.36	15.30	.41	4.13	43.32	13.24	1.14	NA	.10	.57	78.57
1980	.33	14.50	.37	4.17	44.40	14.21	1.38	NA	.11	.61	80.07
1981	.36	14.13	.37	4.17	46.08	15.49	1.89	NA	.10	.59	83.18
1983 5	.43	12.59	.45	3.87	46.70	15.68	4.09	NA	.16	.68	84.64
1985	.45	12.44	1.06	3.58	45.33	18.36	6.25	.05	.37	.53	88.43
1987	.41	12.74	1.08	3.66	45.96	20.61	5.45	.05	.28	.66	90.89
1989	.34	12.47	1.07	3.66	47.40	23.06	4.59	.04	.40	.66	93.68
1991	.32	11.47	.99	3.88	47.02	23.71	4.44	.03	.41	.86	93.15
1993	.30	11.17	1.02	3.92	47.67	25.11	4.10	.03	.50	.91	94.73
1995	.21	10.98	1.06	4.25	49.20	26.77	3.53	.02	.64	1.04	97.69
1997	.18	10.10	.75	5.40	51.05	29.20	1.79	.03	.36	.62	99.49
1999	.17	10.03	.72	5.91	52.37	31.14	1.70	.02	.21	.54	102.80
2001 6	.13	9.81	.65	6.04	54.13	32.41	1.67	.02	.19	.39	105.44
2003	.13	9.50	.64	6.13	54.93	32.34	1.56	.02	.16	.44	105.84
2005	.10	9.38	.55	6.23	56.32	34.26	1.41	.02	.21	.40	108.87
	Percent
1950	33.8	22.1	[4]	2.3	26.0	0.6	9.7	NA	1.8	3.7	100.0
1960	12.2	32.4	[4]	5.1	43.1	1.8	4.2	NA	.4	.9	100.0
1970	2.9	26.0	[4]	6.0	55.2	7.7	1.3	NA	.4	.6	100.0
1973	1.2	24.9	[4]	6.4	55.5	10.4	.9	NA	.2	.7	100.0
1974	1.0	23.8	[4]	5.8	55.7	11.9	.9	NA	.1	.7	100.0
1975	.8	22.5	[4]	5.7	56.4	12.6	1.2	NA	.1	.6	100.0
1976	.7	22.2	[4]	5.7	55.7	13.7	1.2	NA	.1	.6	100.0
1977	.6	20.7	.6	5.6	55.2	14.8	1.6	NA	.2	.7	100.0
1978	.5	20.3	.5	5.4	55.1	15.9	1.4	NA	.2	.8	100.0
1979	.5	19.5	.5	5.3	55.1	16.9	1.4	NA	.1	.7	100.0
1980	.4	18.1	.5	5.2	55.4	17.7	1.7	NA	.1	.8	100.0
1981	.4	17.0	.4	5.0	55.4	18.6	2.3	NA	.1	.7	100.0
1983 5	.5	14.9	.5	4.6	55.2	18.5	4.8	NA	.2	.8	100.0
1985	.5	14.1	1.2	4.1	51.3	20.8	7.1	.1	.4	.6	100.0
1987	.4	14.0	1.2	4.0	50.6	22.7	6.0	.1	.3	.7	100.0
1989	.4	13.3	1.1	3.9	50.6	24.6	4.9	(s)	.4	.7	100.0
1991	.3	12.3	1.1	4.2	50.5	25.5	4.8	(s)	.4	.9	100.0
1993	.3	11.8	1.1	4.1	50.3	26.5	4.3	(s)	.5	1.0	100.0
1995	.2	11.2	1.1	4.4	50.4	27.4	3.6	(s)	.7	1.1	100.0
1997	.2	10.2	.8	5.4	51.3	29.4	1.8	(s)	.4	.6	100.0
1999	.2	9.8	.7	5.7	50.9	30.3	1.7	(s)	.2	.5	100.0
2001 6	.1	9.3	.6	5.7	51.3	30.7	1.6	(s)	.2	.4	100.0
2003	.1	9.0	.6	5.8	51.9	30.6	1.5	(s)	.1	.4	100.0
2005	.1	8.6	.5	5.7	51.7	31.5	1.3	(s)	.2	.4	100.0
1Includes coal coke. 6Beginning in 2001, data are consistent with the 2000 Census.  For 2001 data consistent with the 1990 Census, see American Housing Survey for the United States: 2001. 2Includes briquettes (made of pitch and sawdust), coal dust, waste material (such as corncobs), purchased steam, and other fuels not separately displayed. NA=Not available.  (s)=Less than 0.05 percent.   3In 1950 and 1960, also includes nonreporting units, which totaled 997 and 2,000 units, respectively. Notes:  ·  Includes mobile homes and individual housing units in apartment buildings.  Housing units with more than one type of heating system are classified according to the principal type of heating system. ·  Totals may not equal sum of components due to independent rounding. 4Included in "Distillate Fuel Oil." Web Page:  For related information, see http://www.census.gov/hhes/www/ahs.html. 5Beginning in 1983, the American Housing Survey for the United States has been a biennial survey. Sources:  ·  1950, 1960, and 1970—Bureau of the Census, Census of Population and Housing.  ·  1973 forward—Bureau of the Census, American Housing Survey for the United States, biennial surveys, Table 2-5.