def add_history_trace(dframe, vector, line_shape):
    """Renders the history line"""
    df = dframe.loc[(dframe['REAL'] == dframe['REAL'].unique()[0]) & (
        dframe['ENSEMBLE'] == dframe['ENSEMBLE'].unique()[0])]
    return {'line': {'shape': line_shape}, 'x': df['DATE'], 'y': df[vector],
        'hovertext': 'History', 'hoverinfo': 'y+x+text', 'name': 'History',
        'marker': {'color': 'black'}, 'showlegend': True}
