The yield of ${\mathrm{Mo}}^{99}$ and ${\mathrm{Ag}}^{111}$ relative to ${\mathrm{Ba}}^{140}$ has been measured for proton produced fission in normal uranium. For this type of fission, as well as for fission obtained in other ways, the variation with compound nucleus excitation energy of the ratio of the yield of ${\mathrm{Ag}}^{111}$ to that of ${\mathrm{Ba}}^{140}$ is discussed in terms of the statistical theory of nuclei.