In each of recent and consecutive years of presidential elections, 1000 people of voting age in the

Question:

In each of recent and consecutive years of presidential elections, 1000 people of voting age in the United States were randomly selected and the number who voted was determined, with the results listed below. (The data are the latest available as of this writing.) Comment on the voting behavior of the population.
631 619 608 552 536 526 531 501 551 491 513 553 568