According to figures given out by Michael McDowell last week in a Parliamentary Question regarding FOI requests, 41% more people were being charged a €15 application fee by the Department of Justice in 2006 than in 2004.
More of these figures (including median and average fees charged, and the percentages of requests for which a search and retrieval fee was charged for journalists and the rest of us) can be found on this page. You just scroll down to the table of figures near the end.
If you’d like those figures in a slighly more usable format, here they are in a Comma Seperated Value (CSV) file.