Participating groups counted 168 million adherents in 2010, +38% on 1980; Catholic is the largest tradition (59 million)
Change since 1980: Catholic +24%, Evangelical Protestant +68%, Mainline Protestant +1%. Groups joining or leaving the census move a tradition too, and a blank wave is a tradition whose groups did not report, not zero.
Domestic · Domestic Intelligence · ASARB and Glenmary religion censuses, 1980-2010 (via ARDA) · 30 Dec 2010