def parse_years(year_range):
    """Parse year_range into year list.
    Args:
        year_range: A string in the format aaaa-bbbb.
    Returns:
        A list of years from aaaa to bbbb, including both ends.
    """
    st, ed = year_range.split("-")
    st, ed = int(st), int(ed)
    return [year for year in range(st, ed + 1)]