| Value | Category | 
                                    
                    
                        | 0 |  | 
                                    
                    
                        | 280 |  | 
                                    
                    
                        | 400 |  | 
                                    
                    
                        | 500 |  | 
                                    
                    
                        | 560 |  | 
                                    
                    
                        | 600 |  | 
                                    
                    
                        | 700 |  | 
                                    
                    
                        | 720 |  | 
                                    
                    
                        | 750 |  | 
                                    
                    
                        | 800 |  | 
                                    
                    
                        | 850 |  | 
                                    
                    
                        | 880 |  | 
                                    
                    
                        | 900 |  | 
                                    
                    
                        | 920 |  | 
                                    
                    
                        | 1000 |  | 
                                    
                    
                        | 1050 |  | 
                                    
                    
                        | 1080 |  | 
                                    
                    
                        | 1100 |  | 
                                    
                    
                        | 1120 |  | 
                                    
                    
                        | 1160 |  | 
                                    
                    
                        | 1180 |  | 
                                    
                    
                        | 1200 |  | 
                                    
                    
                        | 1240 |  | 
                                    
                    
                        | 1250 |  | 
                                    
                    
                        | 1280 |  | 
                                    
                    
                        | 1300 |  | 
                                    
                    
                        | 1320 |  | 
                                    
                    
                        | 1350 |  | 
                                    
                    
                        | 1360 |  | 
                                    
                    
                        | 1380 |  | 
                                    
                    
                        | 1400 |  | 
                                    
                    
                        | 1440 |  | 
                                    
                    
                        | 1450 |  | 
                                    
                    
                        | 1460 |  | 
                                    
                    
                        | 1480 |  | 
                                    
                    
                        | 1500 |  | 
                                    
                    
                        | 1520 |  | 
                                    
                    
                        | 1540 |  | 
                                    
                    
                        | 1550 |  | 
                                    
                    
                        | 1560 |  | 
                                    
                    
                        | 1600 |  | 
                                    
                    
                        | 1630 |  | 
                                    
                    
                        | 1640 |  | 
                                    
                    
                        | 1650 |  | 
                                    
                    
                        | 1660 |  | 
                                    
                    
                        | 1670 |  | 
                                    
                    
                        | 1680 |  | 
                                    
                    
                        | 1700 |  | 
                                    
                    
                        | 1750 |  | 
                                    
                    
                        | 1800 |  | 
                                    
                    
                        | 1825 |  | 
                                    
                    
                        | 1840 |  | 
                                    
                    
                        | 1850 |  | 
                                    
                    
                        | 1880 |  | 
                                    
                    
                        | 1900 |  | 
                                    
                    
                        | 1920 |  | 
                                    
                    
                        | 1950 |  | 
                                    
                    
                        | 1960 |  | 
                                    
                    
                        | 2000 |  | 
                                    
                    
                        | 2100 |  | 
                                    
                    
                        | 2200 |  | 
                                    
                    
                        | 2240 |  | 
                                    
                    
                        | 2400 |  | 
                                    
                    
                        | 2500 |  | 
                                    
                    
                        | 2600 |  | 
                                    
                    
                        | 2700 |  | 
                                    
                    
                        | 2147483625 | don't know | 
                                    
                    
                        | 2147483639 | refusal | 
                                    
                    
                        | 2147483640 | skipped | 
                                    
                    
                        | 2147483645 | .x. censored | 
                                    
                    
                        | 10001 | .D | 
                            
            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.