The total costs incurred in the invoice process department of a life insurance company was budgeted at N$1 000 000 for the 2019 year, and N$1 100 000 was actually spent during the year. All the costs incurred in this department are fixed costs. The only activity that this department caries out is the processing of invoices, and the company wishes to charge the costs incurred in this department, to the various business units for which the invoices are processed. The number of company invoices budgeted to be processed for the year was 20 000. The department actually processed 22 000 invoices during the year. The maximum number of invoices that could theoretically be processed by this department in one year is 26 000, but the practical capacity of the department is 25 000 invoices per annum. What is the amount per invoice that the business unit should have been charged, using activity based costing ABC.