code: def providers_count(df):
      
      providers_count = {}
      cnpj_array = df.values
  
      for a in cnpj_array:
          cnpj = a[0]
          occurrences = providers_count.get(cnpj, 0)
          providers_count[cnpj] = occurrences + 1
  
      return pd.DataFrame.from_dict(providers_count, orient='index')
docs: Returns total occurrences of each provider
      in the database.