You are correct that a percentage is a way to express a ratio. I suppose 90% is a "measure" in the context of the question. It assigns a value on a scale from "poor" to "excellent" or from "no questions answered correctly" to "all questions answered correctly."It is not a "position." Position is usually expressed in terms of some amount of distance from a reference in some coordinate system, the units of distance being part of the expression. It is not a count, but may be the ratio of two counts. It is not a label--rather the idea "score" seems to me to be the label here.