It should be noted that the accuracy of Ulrich's classification of journals as open access is limited; open access journals are likely understated. It may be of interest that, according to Ulrich's, new journals have been created in 2006 which are not even online, never mind open access.
Open data and a detailed explanation of the limitations of the data are available at:
Basic data in spreadsheet and chart form follows.
This post reflects my personal opinion only and does not represent the opinions or policy of the BC Electronic Library Network or the Simon Fraser University Library.