Look at the concept of GDP. GDP is not the total value, but the added value of itself. GDP is the final product and service newly created in a certain period of time, so it is an increment in itself. Equal to the sum of the added value of the three major industries.
Industrial added value is statistical, and there are many projects, which are generally reported by enterprises themselves. The simple formula is industrial added value = total output-intermediate input. Each project can also be subdivided.