(1) An expert list of representative rents is a list of representative rents produced according to recognised scientific principles and recognised by the municipality or by representatives of lessors and lessees.
(2) The expert list of representative rents is to be adjusted for market trends at intervals of two years. When this is done, a spot check or the trend of the price index for living standards of all private households in Germany computed by the Federal Statistical Office (Statistisches Bundesamt) may be used as a basis. After four years, a new expert list of representative rents is to be produced.
(3) If the provisions of subsection (2) are complied with, then it is assumed that the payment cited in the expert list of representative rents reflects the reference rent customary in the locality.