Brussels sprout growers are concerned that their vegetable is an "old person's vegetable," that demand is heavily dependent on mature consumers. Last year, consumers 55 and over bought $64.6 million worth of Brussels sprouts. The population includes 38 million potential consumers in this category, with 6 million actually buying Brussels sprouts at least once last year. Overall, the industry sold $121.5 million worth of Brussels sprouts in the United States, where it reckons that there are 163 million potential customers overall. Calculate category development index for consumers age 55 and over for the Brussels sprouts industry. Report your answer as a percent. Round to the nearest tenth of a percent. Report 25.5%, for example, as "25.5".