Via YLE:
In recent years, Finland’s largest cities have developed areas where more than a fifth of the population is of foreign origin. In these city parts, the changeability of people is great, and the original Finnish population continues to decrease.
In Helsinki’s Itäkeskus and other eastern residential areas, for example, more than one fifth of the population have foreign backgrounds, and their number is increasing by about one percent every year.
For her soon-to-be checked doctoral thesis for the University of Helsinki’s Geography Department, researcher Katja Vilkama studied cities’ immigrant concentrations.
According to Vilkama, areas like Itäkeskus are entryways into Finnish society. However, once immigrants start to earn more and become familiar with Finnish society, they often leave these city areas behind.
(source)