Income approach: add up all income earned by household and firms in a single year.
          - W+R+I+P+ statistical adjustments.

Formulas to use:

    - Budget: government purchase of goods and services plus government transfer payments - government tax in the collections.

    - Trade: exports - imports
    -NNP: GNP - depreciation
    - NDP: GDP - depreciation
    - National income: GDP - indirect business taxes - depreciation - net factor for in payments. ( can also use the equation... Compensation of employees + rental income + interest income + proprietor income + corporate income.  )
      - Disposable income: national income - personal household taxes Plus government Transfer payment.