| 
      2017  | 
      2018  | 
    ||||||||
Primary geographical markets  | 
      Group  | 
      SMS  | 
      SMRT  | 
      SMT  | 
      Oth Op  | 
      Group  | 
      SMS  | 
      SMRT  | 
      SMT  | 
      Oth Op  | 
    
Europe  | 
      35,631  | 
      19,826  | 
      6,846  | 
      7,028  | 
      1,931  | 
      38,300  | 
      22,454  | 
      6,773  | 
      8,361  | 
      711  | 
    
North America  | 
      19,852  | 
      7,476  | 
      7,643  | 
      3,420  | 
      1,313  | 
      21,684  | 
      8,356  | 
      9,416  | 
      3,382  | 
      529  | 
    
South America  | 
      4,677  | 
      800  | 
      3,503  | 
      176  | 
      198  | 
      4,992  | 
      825  | 
      3,890  | 
      205  | 
      72  | 
    
Africa and Middle East  | 
      9,205  | 
      334  | 
      8,418  | 
      291  | 
      161  | 
      9,256  | 
      321  | 
      8,544  | 
      329  | 
      60  | 
    
Asia  | 
      18,361  | 
      7,408  | 
      7,380  | 
      2,305  | 
      1,267  | 
      19,763  | 
      8,105  | 
      8,441  | 
      2,771  | 
      446  | 
    
Australia and New Zealand  | 
      6,184  | 
      270  | 
      5,788  | 
      62  | 
      65  | 
      6,930  | 
      281  | 
      6,559  | 
      62  | 
      27  | 
    
Total  | 
      93,906  | 
      36,114  | 
      39,574  | 
      13,281  | 
      4,937  | 
      100,924  | 
      40,343  | 
      43,624  | 
      15,111  | 
      1,846  |