CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (August 15, 2008)
Total no. participating publishers & societies 2,604
% of non-profit publishers 64%
Total no. participating libraries 1,409
No. journals covered 21,014
No. DOIs registered to date 33,052,462
No. DOIs deposited in previous month 315,313
No. DOIs retrieved (matched references) in previous month 10,868,318
DOI resolutions (end-user clicks) in previous month n/a