apartment of which there were 471. There were 88 single room apartments and 162 apartments with six or more rooms. the average price to rent an average apartment in Diessenhofen was 900.07 Swiss francs (CHF) per month (US$720, £410, €580 approx. exchange rate from 2000). The average rate for a one-room apartment was 649.00 CHF (US$520, £290, €420), a two-room apartment was about 628.34 CHF (US$500, £280, €400), a three-room apartment was about 788.98 CHF (US$630, £360, €500) and a six or more room apartment cost an average of 1614.00 CHF (US$1290, £730, €1030). The average apartment price in Diessenhofen was 80.7% of the national average of 1116 CHF. In the 2007 federal election the most popular party was the SVP which received 43.96% of the vote. The next three most popular parties were the SP (16.98%), the CVP (12.61%) and the FDP (11.63%). In the federal election, a total of 909 votes were cast, and the voter turnout was 47.3%. The historical population is given in the following table: Heritage sites of national significance Unterhof Castle, City Archives in the Rathaus (Town council house), Former Dominican Monastery of St. Katharinental with its granary, the zum Goldenen Löwen House and the Goldener Leuen Collection, the Rheinbrücke (Rhine Bridge), and the city walls with Siegelturm are listed as Swiss heritage site of national significance. Both the town of Diessenhofen and St Katharinental Monastery are part of the Inventory of Swiss Heritage Sites. Architecture The Altstadt of Diessenhofen centers on the Siegelturm a tower in which seals and official documents are kept. The old covered bridge over the Rhine was rebuilt in 1814. It leads to Gailingen am Hochrhein in Baden-Württemberg in Germany. Economy One of the three data centers of SWIFT, the international bank messaging network, is situated in Diessenhofen since 2009. , Diessenhofen had an unemployment rate of 1.59%. , there were 74 people employed in the primary economic sector and about 25 businesses involved in this sector. 668 people are employed in the secondary sector and there are 54 businesses in this sector. 901 people are employed in the tertiary sector, with 143 businesses in this sector. there were 2,220 workers who lived in the municipality. Of these, 964 or about 43.4% of the residents worked outside Diessenhofen while 967 people commuted into the municipality for work. There were a total of 2,223 jobs (of at least 6 hours