Americans downloaded more illegal music in October and November than in previously tested periods (the previous test took place in May 2003), despite the best efforts of the Recording Industry Association of America's (RIAA's) lawyers and legal music services such as the Apple iTunes Music Store. An NPD Group study notes that the number of US households using peer-to-peer networks to illegally download music rose 6 to 7 percent during that time period, with 12 million people downloading illegal music. The development marks the first time since May that the figure rose. "It's important to keep in mind that file sharing is occurring less frequently than before the RIAA began its legal efforts to stem the tide of P2P \[peer-to-peer\] file sharing," an RIAA lawyer said. "We're just seeing the first increase in these numbers."