Automation Inc. is a company that provides wireless telecommunications network in several cities in the Midwest region, and the company plans to know more about its customers. The company found that one of his customers has a short customer history of 35, an above-average purchase amount of 75, a low repurchase desirability of 25, a weak product preference of 20, and the customer does not recommend the company's services to potential customers.

Required:
Based on the values provided, what is this customer's loyalty index?