CrossRef Indicators
The latest stats on CrossRef activity have been posted at
http://www.crossref.org/01company/crossref_indicators.html
CROSSREF INDICATORS (January 08, 2009)
Total no. participating publishers & societies 2,684
% of non-profit publishers 64%
Total no. participating libraries 1,445
No. journals covered 21,569
No. DOIs registered to date 34,929,227
No. DOIs deposited in previous month 472,037
No. DOIs retrieved (matched references) in previous month 15,578,632
DOI resolutions (end-user clicks) in previous month 21,225,295