This report is based on aggregated, anonymised data of the APC expenditure of 24 UK higher education institutions, collected by Information Power Ltd on behalf of Jisc Collections in March and April 2014.
The data is available at: http://dx.doi.org/10.6084/m9.figshare.1060243
UPDATE 26 June 2014: A new version of the report has been uploaded today to reflect more accurate APC data that is now available. The analysis of the report has not changed, with the exception that the open access publisher PLOS now features highly.