NMR chemical shift prediction of pyrroles

The chemical shifts of pyrroles can be estimated using substituent chemical shifts (SCS) for the substituents in α (2/5) and β (3/4) positions.
The SCS values used for the calculations are taken from [1].

Literature

[1] "Carbon-13 Nuclear Magnetic Resonance Spectra of Some Substituted Pyrroles"
Abraham RJ, Lapper RD, Smith KM and Unsworth JF J. Chem. Soc., Perkin II (1974) 1004-1009

R2= none Alkyl Ketone/Aldehyde Ester R3= none Alkyl Ketone/Aldehyde Ester R4= none Alkyl Ketone/Aldehyde Ester R5= none Alkyl Ketone/Aldehyde Ester