Or and Gules with three Mullets of the first.Demographics Rheinfelden has a population () of . , 27.6% of the population are foreign nationals. Over the last 10 years (1997–2007) the population has changed at a rate of 6.1%. Most of the population () speaks German (82.9%), with Italian being second most common (3.8%) and Serbo-Croatian being third (2.0%). The age distribution, , in Rheinfelden is; 1,031 children or 9.1% of the population are between 0 and 9 years old and 1,173 teenagers or 10.4% are between 10 and 19. Of the adult population, 1,418 people or 12.6% of the population are between 20 and 29 years old. 1,652 people or 14.6% are between 30 and 39, 1,904 people or 16.9% are between 40 and 49, and 1,544 people or 13.7% are between 50 and 59. The senior population distribution is 1,260 people or 11.2% of the population are between 60 and 69 years old, 790 people or 7.0% are between 70 and 79, there are 441 people or 3.9% who are between 80 and 89, and there are 77 people or 0.7% who are 90 and older. , there were 682 homes with 1 or 2 persons in the household, 2,876 homes with 3 or 4 persons in the household, and 1,250 homes with 5 or more persons in the household. , there were 4,953 private households (homes and apartments) in the municipality, and an average of 2.1 persons per household. there were 958 single family homes (or 15.7% of the total) out of a total of 6,087 homes and apartments. There were a total of 86 empty apartments for a 1.4% vacancy rate. , the construction rate of new housing units was 2.8 new units per 1000 residents. In the 2007 federal election the most popular party was the SP which received 27.64% of the vote. The next three most popular parties were the SVP (26.15%), the FDP (16.05%) and the CVP (11.13%). In the federal election, a total of 2,934 votes were cast, and the voter turnout was 42.9%. The historical population is given in the following table: Heritage sites of national significance The entire old town of Rheinfelden is designated as part of the Inventory of Swiss Heritage Sites. There are seven sites in Rheinfelden that are listed as Swiss heritage sites of national significance. Two religious buildings are on the list, the Christian Catholic collegiate