Electoral system family

Constitution, 2000-03-01 (last amended 2011), http://www.finlex.fi/fi/laki/kaannokset/1999/en19990731.pdf  

Section 25:  The Representativesshall be elected by a direct, proportional and secret vote. Every citizen whohas the right to vote has equal suffrage in the elections. For theparliamentary elections, the country shall be divided, on the basis of thenumber of Finnish citizens, into at least twelve and at most eighteenconstituencies. In addition, the ?land Islands shall form their ownconstituency for the election of one Representative.  […]