Mod Realistic Population 2
Realistic Population 2 by algernon. steam link.
This addon changes buildings to have realistic numbers of households and people. No more single houses with 7 households and huge office buildings with 10 workers. My highscore with this mod has been over 500 workers in an office building and high density residential buildings often have 37 households.
New high score on largest office building workers wise! 
Total of 723 workers in a office building, ok I'll take that 