| Value | Category | Cases | |
|---|---|---|---|
| 1 | random sample | 3774 | 
                                                                 
                                    
                                    72.4%
                                 
                                                             | 
                                                        
                    
| 2 | industrial zone | 502 | 
                                                                 
                                    
                                    9.6%
                                 
                                                             | 
                                                        
                    
| 3 | cluster | 934 | 
                                                                 
                                    
                                    17.9%
                                 
                                                             |