def convert_gdp(gdp):
    """
    converts gdp to a list of dates and a list of gdp's
    :param gdp: list
    :return: list, list
    """
    dates = []
    gdps = []
    for element in gdp:
        dates.append(element[0][2:4])
        gdps.append(element[1])
    return dates, gdps