 In 2002, about 70,962 (53%) listed themselves as Black/African; 31,902 (24%) as mixed; 26,542 (20%) as East Indian; 1,441 (1.1%) as Amerindian; 1075 (0.8%) as Portuguese; 475 (0.35%) as Chinese; 2,265 (1.7%) as "don't know/not stated"; 196 (0.15%) as white not of Portuguese descent; 35 as "other".Georgetown is laid out in a north–south, east–west grid, interlaced with canals protected by kokers (sluices), built by the Dutch and later the British that provide drainage to a city that lies below high-tide level.A long sea wall helps prevent flooding.