Article D2321-11 of the French General Code of Local Authorities
The proportion of capital expenditure financed by own resources is spread over a period of fifteen years in equal annual instalments. For expenditure prior to the facility being brought into service, the starting point for this period is the year in which the facility is brought into service. For expenditure subsequent to the facility being brought into service, the starting point is the year in which the expenditure is incurred.