The line graph illustrates the percentages of house using two different types heating fuels to the years of construction of the houses.
Overall, the percentages of house heating fuel of natural gas showed a sharp decline in older houses during the period, while the newer homes showed a significant rise in the period. In addition, in the beginning, natural gas of the homes used the most prefer, yet it was same paced by electricity for heating of the houses by the end of the period.
In detail, before 1950, the most utilized natural gas of older homes for heating approach 60% and using natural gas of the built remained stable until 1950-1969. During period 1970-1989 there was a dramatic fall to roughly 45% in natural gas of house. Then, there was a continued constant figure by the end of the period.
The other hand, before 1950, the newer built of utilized electricity for heating approximately 15%. This figure increased sharply in 1950-1969 by newer homes of using electricity for heating. 1970-1989, There was a continued rose slightly in houses. 1990-2010 using electricity for heating of houses built showed an increase, approach 45% with equal percentage the using natural gas for heating.