How many Moto GP World titles has Valentino Rossi won?

He won his first World championship in 1997. Won the 250cc world championship in 1999. He won the 500cc World Championship with Honda in 2001.Won the MotoGP World Championship with Honda in 2002 and 2003. He also won in 2004 and 2005 and in 2008 and 2009.