CREATE TABLE table_19778 ("Administrative division" TEXT, "Area  ( km\\u00b2 ) " TEXT, "Population 2000 Census" FLOAT, "Population  ( 2010 Census ) " FLOAT, "Population density 2010  ( /km\\u00b2 ) " FLOAT)

Name the number of population density 2010 for duque de caxias
SELECT COUNT("Population density 2010 (/km\u00b2)") FROM table_19778 WHERE "Administrative division" = 'Duque de Caxias'
SELECT COUNT("Population density 2010 (/km\u00b2)") FROM "table_19778" WHERE "Administrative division" = 'Duque de Caxias'