Fig. 1From: Rising incidence of HPV positive oropharyngeal cancer in Taiwan between 1999 and 2014 where betel nut chewing is commonPrevalence of HPV positive OPC in 408 OPCs across four calendar periods (1999 to 2002, 2003 to 2006, 2007 to 2010, and 2010 to 2014) determined by HPV PCRBack to article page