CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (December 15, 2006)
Total no. participating publishers & societies 2,287
% of non-profit publishers 68%
Total no. participating libraries 1,149
No. journals covered 15,469
No. DOIs registered to date 24,037,590
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