In contrast, the population in the outer boroughs rose continuously, except for a drop in 1945 caused by general war-time conditions. In 1933, the Tempelhof borough had an even higher average population density than the Kreuzberg borough.
While in 1996 a continuous growth in population of up to 300,000 people was expected by 2010, a more complex developement took place: After a peak in 1993 with nearly 3,48 Million inhabitants the number decreased to 3,44 Million in 2000. Since then, the number has increased quite continuously to 3,44 Million inhabitants (Date: 31.12.2009, Amt für Statistik Berlin-Brandenburg). For the whole “Engerer Verflechtungsraum Berlin-Brandenburg” (narrower area of integration) an amount of about 4,4 Million inhabitants is expected by 2020, with 3,36 Million inhabitants for the city of Berlin (cf. SenStadt o.J.).
Lower population density results not only from high proportions of green and open spaces and lesser degrees of development. Lower density can also be due to a large amount of small business, trade and service use, as well as public facilities, etc.. These property areas are included in calculations of population density, as long as they are not separated in an own segment of a block.
Detailed and current data bases of population density in specific urban areas are useful for the planning of various public departments. The Department of Urban Planning, for example, uses these figures as a basis for planning such infrastructure facilities as schools, businesses and playgrounds. Landscape Planning uses these figures for analyzing the number and accessibility of green spaces near to residential areas (cf. Map 06.05, SenStadt 2009). Knowledge of population density also allows conclusions to be drawn regarding environmental stresses, such as calculating emissions from the use of solvents and cleaning chemicals in private residences, and determining carbon dioxide loads (cf. Map 08.03, SenStadtUmTech 1998).