Measured Data

The data are taken from the German Statistisches Bundesamt from the Statistical Yearbook 2006 for Germany [88] (there is also a spreadsheet version available).

Figure 3.2: Measured population data of Germany from 1961 to 2005, see [89]

We will take the data for the population number of the state Baden-Württemberg as starting point. The time window 1961 - 1990 shall be used as base time for the model and the time 1995 - 2005 shall be used for testing the model. The population number of the state Baden-Württemberg shall be called $POP_{t}$ where $t$ is the time unit of a year. Thus we could write:

POP at TIME t	NUMBER [1000]
$POP_{1961}$	7.839,00
$POP_{1970}$	8.954,00
$POP_{1980}$	9.259,00
$POP_{1985}$	9.271,00
$POP_{1987}$	9.330,00
$POP_{1990}$	9.822,00

But these data do not provide any dependency. To get a least one dependency one has to introduce one more parameter which can be related to the parameter $POP$.

POP at TIME t	NUMBER [1000]	NUMBER OF YEARS	CHANGE PER YEAR [%]
$POP_{1961}$	7.839,00	-	-
$POP_{1970}$	8.954,00	9	1.58
$POP_{1980}$	9.259,00	10	0.34
$POP_{1985}$	9.271,00	5	0.03
$POP_{1987}$	9.330,00	2	0.32
$POP_{1990}$	9.822,00	3	1,76
Arithmetic Mean	-	-	0.84

The change rate (ChR) is the new derived parameter which allows now the construction of a simple dependency.