We measured the electricity consumption of 64 buildings separately. The arithmetical mean value is 32 kWh/(m2a) ± 15 kWh/(m2a) (or ±47%) and, of course, is lower
than the thermal consumption of the same group of buildings.
The positive linear correlation between the year of construction and electricity consumption shows an increase in consumption during recent years - an effect which is of high importance. The distribution resulting from this is more or less a standard normal distribution (Fig. 6) and the "Students t-distribution" can again be used. The mean population figures of newer educational buildings in Luxembourg can be evaluated within a range of 32 ± 3 kWh/(m2a) and a probability of 95%.