A census in Württemberg was taken yearly from 1764 to 1806 by locality. The so called Seelenregister (soul registers) can be found in church books. Parallel to these, statistics from 1769 on counted dwellings, cattle and occupations etc. and even a Wanderungsstatistik (journeymen record) was kept.
Spource: Pfister, Christian. Bevölkerungsgeschichte und historische Demographie, page 72 see
After Württemberg joined the Deutsche Zollverein (tariff union) in 1834 every 3 years statistics about the population of Württemberg were produced. After Württemberg joined the Deutsche Reich (1871) every 5 years a census was taken. The earlier statistics asked for male and female and young and old among the population, later much more integrate information was made available. See http://www.landesarchiv-bw.de/sixcms/detial.php?template=hp-artikel&d=17389&:dz=8484&sprache=
The following article by the Max-Planck- Institute explains in more detail the development of census taking throughout Germany with graphics for a quick overview of how each German state handled the issue. Read the article at http://www.demogr.mpg.de/papers/working/wp-2009-023.pdf