Table 4 Consumption of different energy commodities by housetype and household size. Supply of energy per household on average and confidence intervals for energy consumption. 2009

4 Consumption of different energy commodities by housetype and household size. Supply of energy per household on average and confidence intervals for energy consumption. 2009
	Energy consumption on average

	Total energy³	Electricity	Oil and kerosene	Wood, pellets, wood briquettes

	kWh
Total	20 415	15 977	845	3 407

House type
Farm house	30 599	18 818	1 091	10 688
Detached house	25 705	19 919	997	4 717
Rowhouse etc.	17 726	14 764	971	1 723
Flat etc	10 541	9 191	394	589

Household size
1 person	13 811	10 925	579	2 151
2 persons	22 255	16 913	1 060	4 046
3 persons	24 342	19 280	1 120	3 832
4 persons	27 687	22 281	790	4 364
5 and more	30 050	23 322	1 109	5 453

	95 per cent confidence intervals for energy consumption¹^, ²

	Total energy	Electricity	Oil and kerosene	Wood, pellets, wood briquettes

	MWh ( 1 MWh = 1 000 kWh)
Total	19,8-21,1	15,5-16,5	0,6-1,1	3,1-3,7

House type
Farm house	20,8-40,4	12,6-25,0	0-5,0	4,5-16,9
Detached house	24,8-26,6	19,2-20,6	0,6-1,4	4,2-5,2
Rowhouse etc.	15,4-20,1	12,8-16,7	0-1,9	1,0-2,4
Flat etc	7,2-13,9	6,3-12,1	0-1,3	0-2,0

Household size
1 person	7,9-19,7	6,6-15,2	0,0-2,2	0-5,1
2 persons	20,2-24,2	15,5-18,3	0,3-1,8	2,9-5,2
3 persons	21,3-27,4	16,8-21,8	0-2,5	2,3-5,4
4 persons	25,5-29,9	20,6-23,9	0-1,6	3,3-5,5
5 and more	27,4-32,7	21,3-25,3	0-2,6	3,7-7,2

¹	The interpretation of 95 per cent confidence interval is that the true value (average for the group) with 95 per cent probablity is within these limits.
²	The confidence interval is measured as the average +/- 2 times the standard error, divided on the sample in the group divided on the root of the total sample. The lower sample in the group, the larger becomes the uncertainty. There are few one person housholds in the total sample, and this implies a large confidence interval for this group.
³	The difference between total energy and other specified energy commodities, is gas and district heating.