plotting data is too slow

dt = new DataTable();
 dc = new DataColumn();
 dc.ColumnName = "Time"; // x-axis title;
 dt.Columns.Add(dc);
 dc = new DataColumn();
 dc.ColumnName = "Score"; // y-axis title
 dt.Columns.Add(dc);

     for (int i = 0; i < 750; i++)
     {

         Random r = new Random();
         DataRow dr;//add rows
         dr = dt.NewRow();
         dr["Time"] = index;
         dr["Score"] = r.Next(10, 99);
         dt.Rows.Add(dr);

         if (index >= 30)
         {
             DataRow rowRemoved = dt.Rows[0];
             dt.Rows.Remove(rowRemoved);
         }

         dataGridView1.DataSource = dt;
         chart1.DataSource = dt;
         chart1.Series["Series1"].XValueMember = "Time";
         chart1.Series["Series1"].YValueMembers = "Score";
         chart1.DataBind();

         index++;

         Application.DoEvents();
     }