Higher prices at the pump weren't enough to keep consumers away from the stores in May, according to the latest findings of the NRF Executive Opinion Survey, a monthly index by the National Retail Federation (NRF). The Retail Sector Performance Index (RSPI) continued its strong showing in May with a reading of 59.6 points, up 12.1 points from a year ago and up 1.4 points from the previous month (58.2).

The RSPI measures retail executives' evaluations of monthly sales, customer traffic, average transaction per customer, employment, inventories and a six-month-ahead sales outlook expectation. The RSPI is based on a scale of 0.0-100.0, with 50 equaling normal.