Z Order issue

[Mindset]

Hi
I have set my ZOrder as such

            else if (State == State.Historical)
            {

                             SetZOrder(ChartPanel.ChartObjects.Max(co => co.ZOrder));

            }​

However my SharpDX lines still plot behind the Candlesticks whereas I want it on top.
I tried using Min which also doesn't work.
Edit
Doh! The solution is SetZOrder(ChartPanel.ChartObjects.Max(co => co.ZOrder+1));