aggregate default fpf values and user-defined fpf values where enrichment factor calculations will be attempted.
    :param options: SplitInput object
    :return defaults: list includes default fpf values & unique user-defined values

def make_fpfList(options):
    """
    aggregate default fpf values and user-defined fpf values where enrichment factor calculations will be attempted.
    :param options: SplitInput object
    :return defaults: list includes default fpf values & unique user-defined values
    """

    user_values = options.fpf

    defaults = ['0.0001', '0.001', '0.01', '0.05']

    if user_values:
        for fpf in user_values:
            if fpf not in defaults:
                defaults.append(fpf)

        defaults.sort()

    return defaults