def monthly_average(warehouse_name, year, month):

    if warehouse_name in data.keys():
        _data = data[warehouse_name]

        _dates = [list(tmp.keys())[0] for tmp in _data]
        dates = [t.split("-") for t in dates]
        indices = [index for index, date in enumerate(dates) if date[0] == year and date[1] == month]

        filtered_data = [_data[index] for index in indices]

        values = [list(tmp.values())[0] for tmp in filtered_data]

        avg = sum(values)/len(values)

        return avg