A table in the FTI Journal, Spring 2010 at 39, counts new filings of international arbitrations per year going back to 2000. It covers 14 arbitral institutions. In 2008, the top four by number of new filings were AAA-ICDR (US, 703), the International Chamber of Commerce (France, 663), the Hong Kong International Arbitration Center (China, 602), and CIETAC (China, 548). Altogether, the 14 institutions reported 3,000 new filings two years ago.
Filings involving the developing world numbered 1,347 in 2008, while filings of the developed world numbered 1,653.
International arbitration is big business, to be sure, but considered in light of the 60,000 or so law departments in the world, for one in twenty of them to have an international arbitration in a given year casts the data in more human terms.