CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (December 21, 2006)
Total no. participating publishers & societies 2,293
% of non-profit publishers 68%
Total no. participating libraries 1,153
No. journals covered 15,509
No. DOIs registered to date 24,175,589
No. DOIs deposited in previous month 505,729
No. DOIs retrieved (matched references) in previous month 5,623,684
DOI resolutions (end-user clicks) in previous month 15,825,541