11 three family buildings (2.2%) and 38 multi-family buildings (or 7.7%). There were 574 (or 23.3%) persons who were part of a couple without children, and 1,452 (or 59.0%) who were part of a couple with children. There were 103 (or 4.2%) people who lived in single parent home, while there are 32 persons who were adult children living with one or both parents, 7 persons who lived in a household made up of relatives, 25 who lived in a household made up of unrelated persons, and 46 who are either institutionalized or live in another type of collective housing. The vacancy rate for the municipality, , was 0.78%. , the construction rate of new housing units was 7.8 new units per 1000 residents. there were 984 apartments in the municipality. The most common apartment size was the 4 room apartment of which there were 263. There were 9 single room apartments and 248 apartments with six or more rooms. In the 2007 federal election the most popular party was the SVP which received 47.51% of the vote. The next three most popular parties were the CVP (13.77%), the SP (11.76%) and the FDP (11.01%). In the federal election, a total of 837 votes were cast, and the voter turnout was 43.0%. The historical population is given in the following table: Heritage sites of national significance The Gasthof Traube, and Mammertshofen Castle are listed as Swiss heritage site of national significance. The village of Roggwil and the hamlet of Watt bei Roggwil are listed as part of the Inventory of Swiss Heritage Sites. Economy , Roggwil had an unemployment rate of 1.21%. , there were 206 people employed in the primary economic sector and about 59 businesses involved in this sector. 512 people are employed in the secondary sector and there are 27 businesses in this sector. 405 people are employed in the tertiary sector, with 87 businesses in this sector. there were 1,732 workers who lived in the municipality. Of these, 957 or about 55.3% of the residents worked outside Roggwil while 609 people commuted into the municipality for work. There were a total of 1,384 jobs (of at least 6 hours per week) in the municipality. Of the working population, 15.6% used public transportation to get to work, and 51.1% used a private car. Local industry includes the shoe manufacturer kybun Corporation of Karl Müller, pharmaceutical firm A.