  Recently, the calculation of fermionic electroweak two-loop corrections to
the total width of the Z boson and hadronic Z-peak cross-section in the
Standard Model has been presented in arXiv:1310.2256, where "fermionic" refers
to diagrams with closed fermion loops. Here, these results are complemented by
presenting contributions of the same order for the Z-boson partial widths,
which are the last missing pieces for a complete description of Z-pole physics
at the fermionic two-loop order. The definition of the relevant observables and
the calculational techniques are described in detail. Numerical results are
presented conveniently in terms of simple parametrization formulae. Finally,
the remaining theoretical uncertainties from missing higher-order corrections
are analyzed and found to be small compared to the current experimental errors.
