Statistiska centralbyrån and Sture Allén, Staffan Wåhlin, Förnamnsboken, Norstedts 1995, ISBN 9119551622: 19 424 males with the given name Christoffer (compared to 13 061 named Kristoffer) living in Sweden on December 31st, 2010, with the frequency peak in the 1990s. Accessed on 19 June 2011.