To get a "per story" breakdown in the Analysis tables, you usually need to have diaphragms assigned to your floor shells. If you want to verify the numbers , let me know: The building's total area Your typical dead load (PSF or kN/m²)
The mass summary by story report provides a wealth of information about the mass properties of the building. Here's how to interpret the results: etabs mass summary by story
: The direct export from the Display > Show Tables > Structure Output > Other Output Items > Mass Summary by Story . To get a "per story" breakdown in the