ArcGIS REST Services Directory

Generate KML (Demographics/USA_Average_Household_Size)

Document Name:
Layers:
    Average Household Size(0)
      Block Groups(1)
      Tracts(2)
      Counties(3)
      States(4)
Layer Options: All layers as a single composite image (Layers can't be turned on and off in client)
Each layer as a separate image
Vector layers as vectors and raster layers as images