New                                                                           Std                                                                                                        
                                                                                                                                                                                                      
                                                                                                                                    A                                                                 
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                                                                                    no
                                                                                           decision                                                                                                   
                                                                                                                                                                                                      
                                                                                                                                              yes                                                     
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                     B1                                                                                                                                               
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                                                                                      
                                                                                                                                    C