Tri des références dans Biblatex (le retour)

\documentclass[a4paper,oneside]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[american]{babel}
\usepackage{csquotes}

\usepackage[style=numeric,
    defernumbers=true,
    sorting=ydnt, % ordre décroissant des dates
%   sorting=ynt, % ordre croissant des dates
   backend=biber]{biblatex}
\usepackage{hyperref}
\usepackage{nameref}

\DeclareBibliographyCategory{primary}
\DeclareBibliographyCategory{secondary}
\addtocategory{primary}{aristotle:anima,aristotle:physics,averroes/bland}
\addtocategory{secondary}{hyman,moraux,nussbaum,pines}

\addbibresource{biblatex-examples.bib}

\begin{document}
\section*{Prefixed numerical citations}
% Some citations:
\cite{angenendt, kastenholz, augustine, companion, jaffe, ctan}

\nocite{*}

\printbibheading

\printbibliography[heading=subbibliography,title={Primary sources},category=primary,prefixnumbers={P}] 
\printbibliography[heading=subbibliography,title={Secondary sources},category=secondary,prefixnumbers={S}]
\end{document}