Straße were ceded to the 7th District (Neubau). Towards the end of the 19th century, Mariahilf had developed to become an important business district of Vienna. The Mariahilfer Strasse was a major shopping street; however, the big department stores were beyond the district boundary, over in the 7th District. The Mariahilfer area influenced the roads for mainly small and medium-sized businesses. Between 1890 and 1907, the Kaunitzgasse steam power plant became one of the first electricity works in Vienna. Following the acquisition of the originally privately operated power plant, by the municipality of Vienna, it was decommissioned and converted into a substation. "Erinnern für die Zukunft" (Remembrance for the Future) is a memorial project for the many residents of Mariahilf district who were murdered by the Nazi dictatorship in the 1938-1945 period. Mariahilf is home to many of Vienna's gay and lesbian residents and contains a sizable concentration of bars, clubs, restaurants and shops catering to the community, along with the Rosa Lila Villa community center. In the 1990s, there were two minor changes in the district boundaries: in 1995 in the area of the belt on the border at the 15th District, and 1996 in the Europe Square in front of the West Railway Station, where the 6th, 7th and 15th District meet. Both border changes affected mainly the transport structures. The district affiliation of residential areas did not change. Population Population development The Mariahilf District was already, after its 1850 founding, very densely populated. In 1869, the district area had 67,642 inhabitants, a figure that was never surpassed. Until the beginning of the First World War, the population declined only slightly and remained largely stable. After the First World War began, the population almost continuously decreased. However, according to the last census in 2001, the population has largely stabilized and since 2006 has even risen slightly to 29,523 people. Population structure The age of people in Mariahilf, in 2001, differed in several ways from the Vienna citywide averages. So, Mariahilf had fewer children, but more young adults than the average for Vienna. In 2001, the proportion of residents under 15 years was, with 12.4%, below the Vienna value of 14.7%. The population aged 20 to 39 years in Mariahilf was, with 34.4%, more than the Vienna-average of 30.9%. The proportion of the population aged 60 years or more was 19.2%, slightly below the Vienna average (21.7%). The gender