All-over Shampoo is a leading brand in the company's western sales region. Of the 741,000 households in the region, 500,000 purchase the shampoo category. Among this group, 228,000 households purchased All-over shampoo. Households that bought All-over brand shampoo purchased 636,000 bottles of All-over. Those same households purchased 801,000 bottles of shampoo in total. The average consumption of households that bought any brand of shampoo was 2.8 20oz bottles. However, All-over is targeted at heavy users. What is the usage index for households buying All-over brand shampoo in their western region?