Numbers 2D Chart

Is it possible to change the axis numbers assigns to a new data series? My chart is good with one series assigned to the first Y axis and one series assigned to the second Y axis. When I add a third data series it seems to be assigned to the second Y axis by default. I need it to be assigned to the first Y axis for the display to be useful. I have not yet found a way to change the axis to which the third data series is assigned.