I produced a raster map representing estimates of the number inhabitants in pixels of 100x100 meter and I want to calculate the total of inhabitants per administrative units that are represented by polygons such as those shown in the picture. After converting those polygons into a raster layer (with a resolution of 100 meter). I'm using Zonal Statistic as Table in ArcGIS to calculate the number of inhabitants per administrative unit. The resultant table has fewer lines than the number of administrative units represented in the raster layer. Therefore I'm losing information for administrative units having an area below 28500 square meters or for administrative units with an irregular geometry such as those highlighted in the picture. The problem persists when I convert the administrative units into a raster layer with a resolution of 25 meter.
I had a similar issue while using Zonal Statistics as Table. I lost several lines of data in my output table because some of my polygons had the same ID name.
When you indicate your "zone field" in the tool, make sure that whatever field you are choosing has completely unique values. Otherwise, you will lose information in your output table. Hopefully this solves your problem as well!