Why does my cmd.ExecuteNonQuery not work?

public void InsertData(string nim, string name,string angkatan, string thn_msk, string kota_asal)
        {
            using (OleDbConnection con = new OleDbConnection(ConString))
            {
                CmdString = "INSERT INTO MHS (NIM, Nama, Angkatan, [Tahun Masuk], [Kota Asal], [Jenis Kelamin]) VALUES (@NIM, @Nama, @Angkatan, @([Tahun Masuk]), @([Kota Asal]))";
                OleDbCommand cmd = new OleDbCommand(CmdString, con);
                cmd.Parameters.AddWithValue("@NIM", nim);
                cmd.Parameters.AddWithValue("@Nama", name);
                cmd.Parameters.AddWithValue("@Angkatan", angkatan);
                cmd.Parameters.AddWithValue("@([Tahun Masuk])", thn_msk);
                cmd.Parameters.AddWithValue("@([Kota Asal])", kota_asal);
                try
                {
                con.Open();
                MessageBox.Show("Sukses");
                }
                catch (Exception ex)
                {
                    MessageBox.Show(Convert.ToString(ex));
                }
                cmd.ExecuteNonQuery();
                con.Close();