Mapa rozsiedlenia ludności polskiej z uwzględnieniem spisów z 1916 roku.., 1916–1917

(Map of percent of Polish nationals, according to the [March] 1916 German occupation census), Warsaw: solid red = 50% +; horizontal red lines: 31-50%; cross-hatch: 20-30%; diagonal lines: 5-19%.
Interesting, except the German census did not include eastern Belarus or Latgale, where this maps says Poles supposedly comprise 5-19%. As believable as 25% Poles in “Kowno” and parts north.