The Wisconsin Constitution limits the size of the State Assembly to between 54 and 100 members inclusive. Since 1973, the state has been divided into 99 Assembly districts apportioned amongst the state based on population as determined by the decennial census, for a total of 99 representatives. From 1848 to 1853 there were 66 assembly districts; from 1854 to 1856, 82 districts; from 1857 to 1861, 97 districts; and from 1862 to 1972, 100 districts. The size of the Wisconsin State Senate is tied to the size of the Assembly; it must be between one-fourth and one-third the size of the Assembly. Presently, the Senate has 33 members, with each Senate district formed by combining three neighboring Assembly districts.