Municipality, Incorporation into, stands for the integration of a formerly independent municipality into a neighbouring - usually larger - municipality. Mergers of municipalities aim at increasing the number of inhabitants of the individual units of government and so being in the position to offer and to maintain an optimised infrastructure and to promote the growth of towns. In 1891, 1905 and 1938 a number of municipalities were integrated into Vienna, in 1934 similar changes took place in Linz, Salzburg, Innsbruck, Klagenfurt, St. Poelten etc. In the 1960s and 1970s many mergers were effected in Austria, some of them voluntarily and some on order. From 1961-1991 the number of municipalities decreased from 3,931 to 2,333.