CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (September 15, 2006)
Total no. participating publishers & societies 1,679
% of non-profit publishers 64%
Total no. participating libraries 1,100
No. journals covered 15,173
No. DOIs registered to date 22,447,798
No. DOIs deposited in previous month 294,257
No. DOIs retrieved (matched references) in previous month 4,503,094
DOI resolutions (end-user clicks) in previous month 11,007,980