DataTable clone c#

        public DataTable createData() {

            DataTable dt = new DataTable();
            DataRow dr;

            dt.Columns.Add("ID", typeof(string));
            dt.Columns.Add("First Name", typeof(string));
            dt.Columns.Add("Last Name", typeof(string));

            for (int i = 0; i < 30; i++)
            {
                dr = dt.NewRow();
                dr[0] = "id_" + i.ToString();
                dr[1] = "First Name_" + i.ToString();
                dr[2] = "Last Name_"+i.ToString();
                dt.Rows.Add(dr);
            }

            return dt;
        }     


      DataTable dtClone = new DataTable();
            dtClone = dt.Clone();
            DataRow dr;
            int count = (dt.Rows.Count -1);
            for (int j = 1; j < count; j++)
            {
                dr = dtClone.NewRow();
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    dr[i] = Convert.ToDouble(("0." + j).ToString());
                }
                dtClone.Rows.Add(dr);
            }
            gr.DataSet = dtClone;