Fig. 2

a Estimated crude incidence rates of HPV positive OPC across four calendar periods (1999 to 2002, 2003 to 2006, 2007 to 2010, and 2010 to 2014) determined by HPV PCR. Blue line represents the average crude incidence rate of all OPC including man and woman during the 4 calendar years in Taiwan. Red line represents the estimated average crude incidence rate of HPV positive OPC including man and woman during the 4 calendar years in Taiwan. b Estimated crude incidence rates of male HPV positive OPC across four calendar periods (1999 to 2002, 2003 to 2006, 2007 to 2010, and 2010 to 2014) determined by HPV PCR. The blue line represents the average crude incidence rate of all male OPC during the 4 calendar years in Taiwan. The red line represents the estimated average crude incidence rate of male HPV positive OPC during the 4 calendar years in Taiwan