How to do the project budget of property management fee for the project that has not been taken over?

① The revenue budget is calculated according to the total revenue of property service fee × collection rate+parking space service fee+other income.

(2) The expenses are mainly composed of personnel salaries, public energy consumption, greening maintenance fees, cleaning and sanitation fees, order maintenance fees, office expenses, depreciation of fixed assets, public liability insurance, taxes, etc.

How to calculate this specifically, according to the local actual situation, for reference.