Describir: Growth centres and growth cities :

 _    _     _____    _____      _____   __    __   _    _     ______  
| || | ||  |  ___|| |  __ \\   |  ___|| \ \\ / // | || | ||  /_____// 
| || | ||  | ||__   | |  \ ||  | ||__    \ \/ //  | || | ||  `____ `  
| \\_/ ||  | ||__   | |__/ ||  | ||__     \  //   | \\_/ ||  /___//   
 \____//   |_____|| |_____//   |_____||    \//     \____//   `__ `    
  `---`    `-----`   -----`    `-----`      `       `---`    /_//     
                                                             `-`      
 _    _   
| || | || 
| || | || 
| \\_/ || 
 \____//  
  `---`