Number Theory: Are state poll verdicts becoming clearer now?

Most exit polls suggested a close fight in the recently concluded state elections in five states. When votes were counted on December 3, the verdict turned out to be a clear majority for the winner in all five states. In fact, all state elections in past two years except Meghalaya have thrown up a clear verdict. Is what happened this year a break from past trends or was this always the case? Here are four charts that answer this question.