def threshold(suffix, config_dict):
    """Determines null percent thresholds for categories based on suffix."""

    if suffix in config_dict:
        t1 = config_dict[suffix]['cat1']
        t2 = config_dict[suffix]['cat2']
        t3 = config_dict[suffix]['cat3']
    else:
        t1 = config_dict['Categories']['cat1']
        t2 = config_dict['Categories']['cat2']
        t3 = config_dict['Categories']['cat3']

    return t1, t2, t3