Its data, published by the Australian Recording Industry Association, is based collectively on each single's weekly physical and digital sales.
[1] In 2009, 14 singles claimed the top spot, including Lady Gaga's "Poker Face", which started its peak position in late 2008.
Seven acts achieved their first number-one single in Australia, either as a lead or featured artist: Jessica Mauboy, The Fray, Taylor Swift, A. R. Rahman, Nicole Scherzinger, David Guetta, Vanessa Amorosi and Kesha.
[2] The Black Eyed Peas earned three number-one singles during the year for "Boom Boom Pow", "I Gotta Feeling" and "Meet Me Halfway".
[3] Flo Rida's "Right Round", The Black Eyed Peas' "I Gotta Feeling", and Guetta's "Sexy Bitch" each spent seven weeks at the number-one spot.