Swedish emigration in the 1850s

Although I know where two of my Swedish immigrant ancestors came from, I still don't know where others came from. I found the passenger list for one family; my great-great-great-grandmother arrived in New York with her parents and two of her brothers on 8 September 1851 (but didn't stay there; they spent a year in Chicago and then went to Porter County, Indiana). They departed from Gothenburg. Because of the emigration date and the port, they will not be in the EmiHamn database. Her husband's obituary states that he emigrated to America in 1857. Their first child was born 29 August 1858 in Indiana, so they must have married not long after he came to Indiana, and either they had not known each other long, or they knew each other in Sweden (although they would probably not have been involved with each other at the time, since she was 15 when she came to the U.S. and he was 13 years older than her, but the families still may have known each other). If they did know each other in Sweden he may have left from the same port and would not be in EmiHamn either. I have the book Your Swedish Roots by Per Clemensson and Kjell Andersson, and they say that before 1860 all emigrants had to obtain passports and that authorities kept records which had to be sent to the Central Statistics Bureau between 1851 and 1860. The book said that these records are available on microfilm from the Swedish National Archives. I looked at the Web site (http://www.svar.ra.se) but could not find any mention of these records. Any idea how I could get them?