The ARIA Singles Chart ranks the best-performing singles in Australia. Its data, published by the Australian Recording Industry Association, is based collectively on each single's weekly physical and digital sales. In 2012, seventeen singles claimed the top spot, including LMFAO's "Sexy and I Know It", which started its peak position in late 2011. Seventeen acts achieved their first number-one single in Australia, either as a lead or featured artist: Foster the People, Sia, Gym Class Heroes, Neon Hitch, Fun, Janelle Monáe, Carly Rae Jepsen, Karise Eden, Justice Crew, Lupe Fiasco, Psy, Swedish House Mafia, John Martin, Samantha Jade, Macklemore & Ryan Lewis and Wanz.