def calc_lf_improvement(
        param_lf_improved_cy,
        loadfactor_yd_cy
    ):
    """Calculate load factor improvement

    Arguments
    ---------
    lf_improvement_ey : dict
        Load factor improvement until end year provided as decimal (1 == 100%)
    loadfactor_yd_cy : float
        Yd Load factor of current year

    Returns
    -------
    lf_improved_cy : str
        Improved load factor of current year
    peak_shift_crit : bool
        True: Peak is shifted, False: Peak isn't shifed
    """
    # Add load factor improvement to current year load factor
    lf_improved_cy = loadfactor_yd_cy + param_lf_improved_cy

    # Where load factor larger than zero, set to 1
    lf_improved_cy[lf_improved_cy > 1] = 1

    return lf_improved_cy