C#

string strQuery= @"SELECT myID,myItem FROM Table1 WHERE IdCountry=1";
SqlConnection cnnCbx = new SqlConnection(cnnClass.CnnString);
cnnCbx.Open();
SqlDataAdapter daCbx = new SqlDataAdapter(strCbxQueryItems, cnnCbx);
DataTable dtCbx = new DataTable();
daCbx.Fill(dtCbx);
cbxKindOfItems.ValueMember = "myID";
cbxKindOfItems.DisplayMember = "myItem";
cbxKindOfItems.DataSource = dtCbx.DefaultView;

public double Percentile(double[] sequence, double excelPercentile)
        {
            Array.Sort(sequence);
            int N = sequence.Length;
            double n = (N - 1) * excelPercentile + 1;
            // Another method: double n = (N + 1) * excelPercentile;
            if (n == 1d) return sequence[0];
            else if (n == N) return sequence[N - 1];
            else
            {
                int k = (int)n;
                double d = n - k;
                return sequence[k - 1] + d * (sequence[k] - sequence[k - 1]);
            }
        }