It was not a true census since it had limited scope: it only sought to count peasant households (Lithuanian: dūmas) for military purposes.
The Grand Duchy used a conscript army where Lithuanian nobles were required to provide one soldier per each 16 or 20 households owned.
Instead of being a privilege that brought profit from war loot and career opportunities in newly acquired territories, military service became an expensive duty in defense of the motherland.
[2] The state needed ways to enforce the conscription and started keeping detailed lists and inventories of who reported for duty and who did not.
Henryk Łowmiański and Jerzy Ochmański pointed out that Conze did not account for Grand Duke's and church lands that were not counted in the census and increased the estimate to more than 2 million residents.