U.K. online shoppers spent more than 1.5 billion pounds sterling online in May, up 35.6 percent from the 900 million pounds in May of 2004, according to the Interactive Media in Retail Group, reports Internet Retailer. However, total retail sales growth in the U.K. was at its slowest rate since 1947, according to the government statistics, with a year-over-year increase of only 0.9 percent. Sales were up 19.2 percent in March and 29.3 percent in April from the same months in 2004.