| Value | Category | 
                                    
                    
                        | 0 | No Activity Corners | 
                                    
                    
                        | 1 | AC not used | 
                                    
                    
                        | 2 | AC used once/twice | 
                                    
                    
                        | 3 | AC used several times | 
                            
            Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.