Some numbers from a new housing report just caught our collective eye. In 1990, downtown Chicago had about 48,000 housing units, according to housing analyst Appraisal Research Counselors. By the end of 2005, the area had 80,000 units — not including new homes and apartments that had not yet been delivered. When’s it all going to end? By 2008, Appraisal Research predicts, the number of downtown housing units will pass 95,000. The company’s definition of “downtown” is roughly the area bounded by Cermak Rd, North Ave, the lake and Ashland Ave.