| Value | Category | 
                                    
                    
                        | 1 | a foreign language | 
                                    
                    
                        | 2 | how to use a computer | 
                                    
                    
                        | 3 | how to drive a car (with a license) | 
                                    
                    
                        | 4 | nothing | 
                                    
                    
                        | Sysmiss |  | 
                            
            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.