Decarbonylation reaction of $\left[\text{cis}-\left(\mathrm{CH}_{3} \mathrm{CO}\right) \mathrm{Mn}\left({ }^{13} \mathrm{CO}\right)(\mathrm{CO})_{4}\right]$ yields X, Y and Z, where $\mathrm{X}=\left[(\mathrm{CH}_{3}) \mathrm{Mn}(\mathrm{CO})_{5}\right]$; $\mathrm{Y}=\left[\text{cis}-(\mathrm{CH}_{3}) \mathrm{Mn}\left({ }^{13} \mathrm{CO}\right) \mathrm{CO}_{4}\right]$; $\mathrm{Z}=\left[\text{trans}-(\mathrm{CH}_{3}) \mathrm{Mn}\left({ }^{13} \mathrm{CO}\right)(\mathrm{CO})_{4}\right]$. The molar ratio of the products $(\mathrm{X}: \mathrm{Y}: \mathrm{Z})$ in this reaction is