300
They first appeared in "Lollipop", a commercial campaign with Big Bang for LG Electronics, and their debut single "Fire" was released on May 6, 2009. "Clap Your Hands", "Go Away", and "Can't Nobody" were all released on September 9, 2010, as promotional singles, and were followed by "It Hurts (Slow)".
Who is 2NE1?