Pool Of Independent Brokers Grows As Wall Street's Falls By Lynn Cowan and Cheryl Winokur Munk of DOW JONES NEWSWIRES WASHINGTON--(Dow Jones)--They're not affiliated with well-known names such as Merrill Lynch & Co. (MER) or Citigroup Inc.'s (C) Smith Barney, but the ranks of independent stockbrokers have continued to grow in the past three years even as major Wall Street firms have consistently been cutting their sales forces. The number of independent brokers - who shoulder all the costs of doing business but get to keep a greater portion of their output - increased 37% from 1999 to an estimated...