You can blame upper-income Americans for many things, but don't blame them for the restaurant industry's lackluster performance. Based on a Gallup poll conducted last month, the chart here gives dining-out data for adults in general. Among respondents with annual household income of $75,000 or higher, by contrast, 40 percent dined out three or more times in the week before being polled; 49 percent dined out once or twice during that week. Conversely, just 11 percent of these upper-income respondents hadn't dined out at all in the previous week, vs. 19 percent of those in the $50,000-74,999 bracket, 24 percent in the $30,000-49,999 cohort and 32 percent of those making under $30,000. By standards of earlier times, though, dining out is remarkably common at all levels of income. Even among respondents in the under-$30,000 income cohort, 19 percent reported dining out three or more times in the previous week. That's partly because restaurant dinners are routine among young adults, who tend to be on the lower end of the income scale. Among adults age 18-34, 37 percent dined out three or more times during the week before being surveyed; just 18 percent hadn't done so even a single time. Among respondents age 55 and older, 24 percent dined out three times during that period, while 25 percent made it through the week without ever darkening a restaurant's door at dinner time. Unfortunately for the nation's restaurateurs, young adults are less likely than their elders to spend lavishly when they do dine out.