The Culture Monster blog did their homework and read through the just-released NEA report on cultural attendance. The worst news is for Classical music and jazz. After that,

Nearly 35% of U.S. adults – or about 78 million people – attended an art museum or an arts performance in 2008, said the report. That’s down from about 40% in 1982, 1992 and 2002. […]

Surprisingly, the largest drop in arts consumption comes from people ages 45 to 54, which has traditionally been the most dependable group of arts participants.

— The U.S. rate of attendance for art museums fell from a high of 26% in 1992-2002 to 23% in 2008, comparable to the 1982 level.

NEA Reports Decline in Arts Audiences for 2008 (Culture Monster)