OP, bare in mind that measured test results are only useful when one is aware of the make/model of vacuums tube tester that measured those results if they were tested on a mutual conductance tester, as a Hickock 6000A will produce a different set of test figures for a 100% Tube to those of an AVO 160, you need to know the scale for the valve in question on the tester in question.
Measured test results are generally a very good indicator of the useful life of a tube.
In a simplistic hypothetical scenario if your valve has a scale of 100/100 = NOS
and 60/60 as borderline usable then one can draw some conclusions about a valve that measures 98/96 against a second tube that measures 76/72.