n grade                                                                                                                NS             NS                                                     Grade 0                       0              0              0              0              0                                                                     Grade 0                       00             00             0              0              0                                                                     Grade 0                       00             00             00             0              00                                                                    Grade 0                       00             0              0              0              0                                                                     Grade 0                       0              0              0              0              0                          