CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (June 06, 2008)
Total no. participating publishers & societies 2,558
% of non-profit publishers 64%
Total no. participating libraries 1,375
No. journals covered 20,701
No. DOIs registered to date 32,312,478
No. DOIs deposited in previous month 358,998
No. DOIs retrieved (matched references) in previous month 10,660,746
DOI resolutions (end-user clicks) in previous month 21,928,242