Subprime lenders provided most of the muscle for a sluggish mortgage market during the first half of 2004. Inside Mortgage Finance estimates that $252.6 billion in new subprime mortgage loans were made in the first six months of 2004, an 87.1 percent year-to-year increase that capped the best six-month period on record for the sector. Subprime lenders saw their business rise by a healthy…