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24. Deferred revenue
12 Months Ended
Dec. 31, 2019
Deferred Revenue  
Deferred revenue
     12.31.19    12.31.18
Non-current        
Nonrefundable customer contributions     270,091     423,539
Total Non-current     270,091     423,539
         
         
     12.31.19    12.31.18
Current        
Nonrefundable customer contributions      5,346      8,221
Total Current      5,346      8,221