C# - Assign A Value To Special Footer Column In Gridview

I have a Gridview like this;

In my .cs file i calculate value of BV, MV, KV total value with this code and i assign to a Label. Labels are under the Gridview. BUT, some customer names long some of short, because of that, labels location changing according to Gridview. Because of that i don't want use Label.

I calculate a value with this code, and how can i assing BV, MV and KV columns footer this value?

double sumRISK = 0;
foreach (GridViewRow gvr in GridView1.Rows)
{
CheckBox cb = (CheckBox)gvr.FindControl("NameCheckBoxField1");
if (cb.Checked == true)
{
double amountBV = Convert.ToDouble(gvr.Cells[7].Text);
if (amountBV != -1)
{
sumRISK += amountBV;
}
}
}
RISK_Label.Text = String.Format("{0:n}", sumRISK);