between 20 and 29 years old. 19 people or 6.4% are between 30 and 39, 34 people or 11.5% are between 40 and 49, and 61 people or 20.7% are between 50 and 59. The senior population distribution is 48 people or 16.3% of the population are between 60 and 69 years old, 34 people or 11.5% are between 70 and 79, there are 32 people or 10.8% who are over 80. , there were 147 private households in the municipality, and an average of 2. persons per household. there were 337 single family homes (or 75.7% of the total) out of a total of 445 inhabited buildings. There were 61 two family buildings (13.7%) and 27 multi-family buildings (6.1%). There were also 20 buildings in the municipality that were multipurpose buildings (used for both housing and commercial or another purpose). The vacancy rate for the municipality, , was 0.85%. there were 582 apartments in the municipality. The most common apartment size was the 3 room apartment of which there were 150. There were 86 single room apartments and 90 apartments with five or more rooms. Of these apartments, a total of 147 apartments (25.3% of the total) were permanently occupied, while 429 apartments (73.7%) were seasonally occupied and 6 apartments (1.0%) were empty. , the construction rate of new housing units was 0 new units per 1000 residents. The historical population is given in the following tables: Heritage sites of national significance The Palazzo Della Barca and the Museo Onsernonese are listed as Swiss heritage site of national significance. The villages of Comologno, Russo, Gresso, Mosogno di sotto, Auressio, Berzona and Loco are part of the Inventory of Swiss Heritage Sites. Politics In the 2011 federal election the most popular party was the SP with 36.0% of the vote. The next three most popular parties were the FDP (24.3%), the CVP (18.0%) and a party or parties listed as other (6.6%). In the federal election, a total of 120 votes were cast, and the voter turnout was 35.5%. In the 2007 federal election the most popular party was the SP which received 29.95% of the vote. The next three most popular parties were the FDP (27%), the CVP (16.98%) and the SVP (12.62%). In the federal election, a total of 116 votes were cast, and the voter turnout was 30.3%. In the Gran Consiglio election, there were a total