After a successful appeal to the Government Information Act by critical students, the Association of universities in the Netherlands (VSNU) published an overview per university of subscription rates of scholarly publications of big publishers like Springer and Elsevier. The costs for open access publishing are included. To this day, publishers do not allow access to these data.
According to the explanation on de VSNU site, the data of the University of Amsterdam (UvA) are not yet correct: the total amount is right, however the separate amounts still need to be corrected.
Dutch National website providing information for academics about the advantages of open access to publicly financed research