RCA had success in the format with their top money earner, Elvis Presley, issuing 28 Elvis EPs between 1956 and 1967, many of which topped the separate "Billboard" EP chart during its brief existence. Other than those published by RCA, EPs were relatively uncommon in the United States and Canada, but they were widely sold in the United Kingdom, and in some other European countries, during the 1950s and 1960s. In Sweden EP was for long the most popular record format, with as much as 85% of the market in the late 1950s being EPs.