The first census for Baden was taken in 1811 and repeated every year. These censuses were for statistical purposes showing that between 1811 and 1852 the population grew from 1 mill. to 1.3 mill. Since 1864 the censuses looked at individual households.
Read more about census taking in Germany at http://www.demogr.mpg.de/papers/working/wp-2009-023.pdf