Every taxpayer who claims credit under this article shall maintain sufficient records to establish the following facts for each item of certified eligible safety property:
(1) Its identity;
(2) Its actual or reasonably determined cost;
(3) Its straight-line depreciation life;
(4) The month and taxable year in which it was placed in service;
(5) The amount of credit taken; and
(6) The date it was disposed of or otherwise ceased to be actively and directly used in a coal mine in this state.