Sunshine Juices sold $$17\mathrm{.}3$ million in the U$.$S$.$ pomegranate juice drink market last year, but the $10\mathrm{.}4$ million customers who bought from Sunshine Juices spent a total of $$35\mathrm{.}2$ million in this market. Across the whole marketplace, $72\mathrm{.}4$ million buyers contributed to total industry sales of $$209\mathrm{.}9$ million of pomegranate juice drinks. Calculate usage index for Sunshine Juices' customers in the U$.$S$.$ pomegranate juice drink market. Report your answer as a percent, and round your answer to the nearest tenth of a percent. Report $27\mathrm{.}5\%,$ for example, as $"27\mathrm{.}5".$