Annual sales of contemporary art slumped 75 percent at the two largest auction houses’ evening sales in 2009. Sotheby’s and Christie’s International made a combined total of $482.3 million with fees from their five regular “Part I” sales of high-value art in New York and London, down from $1.97 billion in 2008. (Both auction houses sold undisclosed amounts in private sales.) The auction market regained confidence with Sotheby's $43.8 million Andy Warhol, “200 One Dollar Bills”...