Freddie Mac regained the top ranking in issuance of agency-backed real estate mortgage investment conduits last year, pumping out $197.1 billion of deals over the course of 2004. While that was down 6.5 percent from the company’s REMIC production in 2003, it was more than enough to claim top ranking in a market that shrank 38.3 percent. Total agency-backed REMIC issuance in 2004 was $318.5 billion, the lowest volume since year 2000. …