To make statements about the evolution of suicide frequency, one has to analyse long periods. The Federal Bureau of Statistics disposes of data since 1876. When treating the statistics material of such as long period, changes in the "dark-numbers" have to be considered for they can simulate (false) tendencies. There are various reasons to assume that the dark-numbers today are smaller than at the end of the last and at the beginning of this century. A separated analysis according to age-groups brings more specific results for the size of the dark-number as well as its changes varies from age-group to age-group. In Switzerland the suicide rate of males above 30 years of age is low presently than at the begining of this century, whereas the suicide rate of males below 30 years (without regard to fluctuations) is practically the same. Since the Second World War, the suicide rate of females oscillates within a range of near-constancy. Prospective statements cannot be made. The calculated suicide rates since 1971 are only provisonal, for the basic population sizes are estimated.