Calculate joint distribution of 2 raster data

[nik_geo]

Hi, I want to calculate the Night Light Development Index (NLDI). For this reason I have a data set of raster:

• night-time lights satellite image
• population count raster.

The rasters have the same extent, dimensions and CRS. In order to calculate the NLDI I need to compute the joint distribution of the rasters and to create a table like in the image attached. Is there a way to compute the population count by night-time lights class? I tried to do it in an other GIS software using a command called Cross-tabulation but the result was wrong. The paper I am following is named "An empirical assessment of human development through remote sensing_Evidences from Italy". The dataset can be found here. Thank you.population count by night-time light level class