Since K-pop started to spread its industry outside South Korea, K-pop artists have set notable records on YouTube. Of the 2.28 billion worldwide K-pop YouTube views in 2011, 240 million came from the United States, more than double the figure from 2010 (94 million). In December 2011, K-pop became the first country-specific genre of music to gain a homepage on YouTube. In December 2012, Psy's music video for "Gangnam Style" became the first YouTube video to receive 1 billion views. In 2016 the music video for the song "TT" by Twice became the first video by a female Korean act with over 400 million YouTube views. On January 21, 2019, girl group Blackpink's music video Ddu-Du-Ddu-Du became the highest viewed K-pop group music video on YouTube. On April 12, 2019, BTS' music video for "Boy with Luv" set a record for the most viewed online music video in the first 24 hours, garnering over 74 million views.