def yob_clean(y):# {{{
    """
    Clean year of birth

    Parameters
    y: float or None

    Returns
    int

    Notes
    None: missing data
    """
    if y is None:
        return None
    elif isinstance(y, float):
        return int(y)
    elif isinstance(y, int):
        return y
    elif isinstance(y, str):
        return int(float(y))
    else:
        return None