y                    x                                                     
77.4               150                                                          
76.7               150                                                          
78.2               150                                                          
84.1               200                                                          
84.5               200                                                          
83.7               200                                                          
88.9               250                                                          
89.2               250                                                          
89.7               250                                                          
94.8               300                                                          
94.7               300                                                          
95.9               300