def minus_df(dfsuper, dfsub):
    """
    dfsuper - dfsub : returns rows that exist in dfsuper and not in dfsub
    """
    dfsuper = dfsuper.set_index('Company ID')
    dfsub = dfsub.set_index('Company ID')
    df = dfsuper[~dfsuper.index.isin(dfsub.index)]
    return df
