were 263 two family buildings (8.0%), 132 three family buildings (4.0%) and 638 multi-family buildings (or 19.3%). There were 5,189 (or 23.6%) persons who were part of a couple without children, and 10,577 (or 48.2%) who were part of a couple with children. There were 1,346 (or 6.1%) people who lived in single parent home, while there are 126 persons who were adult children living with one or both parents, 101 persons who lived in a household made up of relatives, 239 who lived in a household made up of unrelated persons, and 772 who are either institutionalized or live in another type of collective housing. The vacancy rate for the municipality, , was 1.15%. , the construction rate of new housing units was 3.6 new units per 1000 residents. there were 10,470 apartments in the municipality. The most common apartment size was the 4 room apartment of which there were 3,198. There were 537 single room apartments and 1,091 apartments with six or more rooms. the average price to rent an average apartment in Frauenfeld was 1087.26 Swiss francs (CHF) per month (US$870, £490, €700 approx. exchange rate from 2000). The average rate for a one-room apartment was 508.43 CHF (US$410, £230, €330), a two-room apartment was about 761.63 CHF (US$610, £340, €490), a three-room apartment was about 960.43 CHF (US$770, £430, €610) and a six or more room apartment cost an average of 1936.19 CHF (US$1550, £870, €1240). The average apartment price in Frauenfeld was 97.4% of the national average of 1116 CHF. In the 2007 federal election the most popular party was the SVP which received 34.4% of the vote. The next three most popular parties were the SP (15.55%), the CVP (15.03%) and the FDP (13.5%). In the federal election, a total of 7,105 votes were cast, and the voter turnout was 48.5%. Historical population The historical population is given in the following table: Heritage sites of national significance There are ten buildings that are listed as Swiss heritage site of national significance in Frauenfeld. There are four archives and a library on the list; archive of the Amtes für Denkmalpflege, the archive of the Department of Archeology, the Citizen's Archive of Frauenfeld, the State Archives of the Canton and Cantonal Library. The Catholic City Church and the Simultaneum Church of St Laurenzen with St Anna Chapel and Messmerhaus are the two religious buildings on the