   defp parse_and_calculate_monthly_payroll(dbf_file, month, employees) do
     tax_year =
       cond do
+        month > "1912M" -> 2020
         month > "1812M" -> 2019
         month <= "1812M" -> 2018
       end

    earned_salary =
      Decimal.round(Decimal.mult(emp.base_salary, Decimal.div(emp.days_worked, 27)), 2)

    ssnit_amount = Decimal.round(Decimal.mult(Decimal.div(emp.ssnit_ded, 100), earned_salary), 2)

    {ssnit_emp_contrib, ssnit_total, ssnit_tier_1, ssnit_tier_2} =
      case emp.id === "E0053" do
        true ->
          # 12.5 div 5
          ssnit_emp_contrib =
            Decimal.round(Decimal.mult(Decimal.from_float(2.5), ssnit_amount), 2)

          ssnit_total = Decimal.add(ssnit_amount, ssnit_emp_contrib)
          ssnit_tier_1 = ssnit_total
          ssnit_tier_2 = Decimal.new(0)
          {ssnit_emp_contrib, ssnit_total, ssnit_tier_1, ssnit_tier_2}

        false ->
          # 13 div 5.5

    end
  end

  defp gra_income_tax(i, 2020) do
    cond do
      Decimal.compare(i, Decimal.new("319")) != :gt ->
        Decimal.new("0")

      Decimal.compare(i, Decimal.new("419")) != :gt ->
        Decimal.round(Decimal.mult(Decimal.sub(i, 319), Decimal.new("0.05")), 2)

      Decimal.compare(i, Decimal.new("539")) != :gt ->
        Decimal.round(
          Decimal.add(Decimal.mult(Decimal.sub(i, 419), Decimal.new("0.1")), Decimal.new("5")),
          2
        )

      Decimal.compare(i, Decimal.new("3539")) != :gt ->
        Decimal.round(
          Decimal.add(
            Decimal.mult(Decimal.sub(i, 539), Decimal.new("0.175")),
            Decimal.new("17")
          ),
          2
        )

      Decimal.compare(i, Decimal.new("20000")) != :gt ->
        Decimal.round(
          Decimal.add(
            Decimal.mult(Decimal.sub(i, 3539), Decimal.new("0.25")),
            Decimal.new("542")
          ),
          2
        )

      true ->
        Decimal.round(
          Decimal.add(
            Decimal.mult(Decimal.sub(i, 20000), Decimal.new("0.3")),
            Decimal.new("4657.25")
          ),
          2
        )
    end
  end

  defp gra_income_tax(i, 2019) do
    cond do
      Decimal.compare(i, Decimal.new("288")) != :gt ->
