def make_normaliser(data, year, value, keep_vars):
    """Creates a table with prepandemic activity
    Args:
        data (df): table we want to extract the baseline from
        year (int): baseline year
        value (str): value var
        keep_vars (list): variables to keep
    """
    pre_c = (
        data.query(f"{value}>0")
        .query(f"year=={year}")[keep_vars]
        .rename(columns={value: f"{value}_rescaler"})
    )
    return pre_c