<Li> An estimated 5 million devotees attended the Bishwa Ijtema in Bangladesh in 2010 . </Li> <Li> An estimated 5 million people gathered in Sabarimala, India on 14 January 2007 to watch' Makarajyothi', a bright flame that flickers three times on a remote hillside of Ponnambalamedu . </Li> <Li> An estimated 4.2 million people attended a concert given by Rod Stewart in Rio de Janeiro, Brazil on 31 December 1994 . </Li> <Li> Over 4 million people flocked to Karbala on the day of Ashoura in the shines of Imam Husain and his younger paternal half brother Mola Abbas in 2010 . </Li>

Where is the world’s largest annual migration according to the bbc