But there is growing evidence that infection in the mouth with HPV is a major cause of oral cancer.Around 25% of mouth and 35% of throat cancers are HPV-related, but the exact figures vary between different studies, possibly due to different ways of testing for the virus, or varying levels of smoking and other risk factors. It shows the male to female sex ratio as estimated by United States' CIA.However, there are differences between the estimates by The World Factbook and numbers reported by the census offices of respective countries.Detecting the HPV virus in a sample of people who have oral cancer does not mean that HPV caused the cancer.The virus becomes part of the genetic material of the cancer cells, triggering them to grow.The world average for the ratio of males/females is 1.01, which means there are (more) 1.01 males for (fewer) 1.00 females.For example, The World Factbook in 2001 reported Switzerland's sex ratio at birth as 1.05, Similar differences between estimates by "The World Factbook" and census numbers from birth records are known for Sweden, Norway, Ireland, India and Japan. 1.1, means there are 1.1 males for every 1 female (more males than females). 0.8, means there are 0.8 males for every 1 female (more females than males).
A ratio of 1 means there are equal numbers of females and males.
In England, around 5,400 people were diagnosed with oral cancer in 2011.