Christian Larson, 1871

I have been searching for the ship on which my g. g. grandparents emigrated. In the Digitalarkivet they are listed under "Emigrants from Oslo 1867-1930", as follow: Harbour No. 23586 Oslo 471A, 1871 Juni 10 Christian Larsen Nordhagen, male, married, age 36, residence Ringsaker. with his family: 471B, Anne Olsen, f. Kone, age 37 471C Mathias, m. u. age 12 471D Ole, m. u. age 1.5 year Christian and Anne settled in Vernon Co., Wis. and he died in 1932 in Westby, WI at the age of 97. Anne preceded him in death. Mathias was known as Martin Larson in America and he was my g. grandfather. Ole died as a young man. In another Digitalarkivet records, "Uttflytta fra Ringsaker 1814-1925" I find the same information except both he and his wife are listed as 40 which is wrong. Why can't I find them on any passenger lists?