Where it is not possible for purposes of this act, to determine the average ratio in any taxable district by reason of the fact that there are no usable real estate sales during the period referred to in section 1. a. of this act, the director may consider such other data and studies as may be available and he may make such further and different investigations of assessment practices as he may deem necessary or desirable for establishing the “average ratio” required by this act.

L.1973, c. 123, s. 6, eff. May 9, 1973.