Surveys in Domorica indicate that only 10 percent of Domoricans in their twenties read a newspaper regularly, while more than half of all Domoricans over thirty read a newspaper regularly. Although Domoricans in their twenties constitute a large proportion of the population, newspaper publishers nonetheless predict that ten years from now, the percentage of Domoricans who regularly read a newspaper will probably be no lower than it is today.

Which of the following, if true, provides the strongest grounds for the newspaper publishers' prediction?