Also, in the intro you say "the risk of skin cancer increases exponentially with age and is associated with accumulation of somatic mutations8". Your source groups ages into only 3 categories... If you look closer at the data you will see that developing most cancers becomes less common in old age (peaks at 60 - 90 years old). For cancers involving tissue like bone or reproductive organs this peaks much earlier, probably due to when the majority of cell divisions are occurring.