Online mortgage lenders produced $6.04 billion less in 2000 than in 1999, according to data recently released by federal banking regulators, probably because of the closing of many pure-play online lenders. The 15 largest lenders that do all or a large portion of their mortgage business online produced a combined $13.64 billion in production in 2000. That is a drop of 30 percent from the $19.68 billion in 1999 produced by the top 13 online