CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (March 09, 2007)
Total no. participating publishers & societies 2,340
% of non-profit publishers 66%
Total no. participating libraries 1,193
No. journals covered 16,884
No. DOIs registered to date 25,325,745
No. DOIs deposited in previous month 585,846
No. DOIs retrieved (matched references) in previous month 5,486,433
DOI resolutions (end-user clicks) in previous month 13,290,774