Here we are: Rev Gareth Leyshon's work on Catholic demographics here http://www.drgareth.info/demographics.shtml and a set concerned with ordinations in particular (to be used with caution given the source - it was a salvo in a heated debate on this very topic a few years ago) at http://www.lms.org.uk/resources/statistics-from-the-catholic-directory . I was incorrect about 1959 but I may have been thinking of entries into the seminary - on average it is six years from entry to ordination at the moment. The lms graph for ordinations per 100,000 is probably more significant than the absolute numbers.